{ "title": "MCP Tools, Resources, and Prompts — Reader FAQ", "schemaVersion": "1.0", "researchFreeze": "2026-08-26", "protocolRevision": "2026-07-28", "publicationNote": "All answers are intended for visible reader content; this endpoint does not imply FAQ rich-result eligibility.", "count": 50, "records": [ { "id": "R6-FAQ01", "question": "What are MCP tools, resources, and prompts?", "answerMarkdown": "They are three server-side primitives: operations, URI-addressable data, and reusable message templates.", "answer": "They are three server-side primitives: operations, URI-addressable data, and reusable message templates.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ02", "question": "What is the main difference between an MCP tool and resource?", "answerMarkdown": "A tool represents an operation; a resource represents data with a durable URI identity.", "answer": "A tool represents an operation; a resource represents data with a durable URI identity.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ03", "question": "What is the main difference between a resource and prompt?", "answerMarkdown": "A resource is data; a prompt is a message template describing how to begin or structure an interaction.", "answer": "A resource is data; a prompt is a message template describing how to begin or structure an interaction.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ04", "question": "What is the main difference between a tool and prompt?", "answerMarkdown": "A tool executes or delegates work; a prompt returns messages that may lead to later work.", "answer": "A tool executes or delegates work; a prompt returns messages that may lead to later work.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ05", "question": "Who controls MCP tools?", "answerMarkdown": "The intended model is model selection mediated by the host, which controls visibility and permission.", "answer": "The intended model is model selection mediated by the host, which controls visibility and permission.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ06", "question": "Who controls MCP resources?", "answerMarkdown": "The host/application controls listing, reading and insertion into context, although users and models may influence selection.", "answer": "The host/application controls listing, reading and insertion into context, although users and models may influence selection.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ07", "question": "Who controls MCP prompts?", "answerMarkdown": "The server authors them, the host surfaces them, and the user explicitly selects them.", "answer": "The server authors them, the host surfaces them, and the user explicitly selects them.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ08", "question": "Does every server need all three?", "answerMarkdown": "No.", "answer": "No.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ09", "question": "Can one server expose all three?", "answerMarkdown": "Yes.", "answer": "Yes.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ10", "question": "Can a tool be read-only?", "answerMarkdown": "Yes.", "answer": "Yes.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ11", "question": "Can a resource change?", "answerMarkdown": "Yes; current MCP supports requested update streams.", "answer": "Yes; current MCP supports requested update streams.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ12", "question": "Can prompts include resources?", "answerMarkdown": "Yes, through resource links or embedded resources.", "answer": "Yes, through resource links or embedded resources.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ13", "question": "Can tools return resources?", "answerMarkdown": "Yes.", "answer": "Yes.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ14", "question": "Can resources be binary?", "answerMarkdown": "Yes.", "answer": "Yes.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ15", "question": "Can tool results contain images?", "answerMarkdown": "Yes.", "answer": "Yes.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ16", "question": "Can prompt messages contain audio?", "answerMarkdown": "Yes under the current content model.", "answer": "Yes under the current content model.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ17", "question": "Are resources always files?", "answerMarkdown": "No.", "answer": "No.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ18", "question": "Are resource URIs public URLs?", "answerMarkdown": "Not necessarily; custom schemes are common.", "answer": "Not necessarily; custom schemes are common.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ19", "question": "What is a resource template?", "answerMarkdown": "A parameterized URI definition for a family of resources.", "answer": "A parameterized URI definition for a family of resources.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ20", "question": "Do resource templates use RFC 6570?", "answerMarkdown": "MCP uses URI-template concepts aligned with RFC 6570.", "answer": "MCP uses URI-template concepts aligned with RFC 6570.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ21", "question": "What method lists tools?", "answerMarkdown": "tools/list.", "answer": "tools/list.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ22", "question": "What method invokes tools?", "answerMarkdown": "tools/call.", "answer": "tools/call.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ23", "question": "What method lists resources?", "answerMarkdown": "resources/list.", "answer": "resources/list.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ24", "question": "What method reads resources?", "answerMarkdown": "resources/read.", "answer": "resources/read.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ25", "question": "What method lists resource templates?", "answerMarkdown": "resources/templates/list.", "answer": "resources/templates/list.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ26", "question": "What method lists prompts?", "answerMarkdown": "prompts/list.", "answer": "prompts/list.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ27", "question": "What method retrieves a prompt?", "answerMarkdown": "prompts/get.", "answer": "prompts/get.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ28", "question": "What happened to resources/subscribe?", "answerMarkdown": "It is a legacy method; current MCP uses subscriptions/listen with resource filters.", "answer": "It is a legacy method; current MCP uses subscriptions/listen with resource filters.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ29", "question": "Are tool lists cacheable?", "answerMarkdown": "Yes under the 2026-07-28 cache-hint model.", "answer": "Yes under the 2026-07-28 cache-hint model.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ30", "question": "Are resource reads cacheable?", "answerMarkdown": "Yes, subject to TTL and cache scope.", "answer": "Yes, subject to TTL and cache scope.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ31", "question": "Are prompt lists cacheable?", "answerMarkdown": "Yes.", "answer": "Yes.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ32", "question": "Are tool-call results automatically cacheable?", "answerMarkdown": "No universal rule makes every execution result cacheable.", "answer": "No universal rule makes every execution result cacheable.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ33", "question": "What is structuredContent?", "answerMarkdown": "Server-produced JSON-like structured tool output.", "answer": "Server-produced JSON-like structured tool output.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ34", "question": "What is outputSchema?", "answerMarkdown": "An optional schema describing a tool’s structured output.", "answer": "An optional schema describing a tool’s structured output.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ35", "question": "What are tool annotations?", "answerMarkdown": "Untrusted behavior hints such as read-only or destructive.", "answer": "Untrusted behavior hints such as read-only or destructive.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ36", "question": "Are tool annotations security guarantees?", "answerMarkdown": "No.", "answer": "No.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ37", "question": "What is a resource link?", "answerMarkdown": "A content item pointing to a separately addressable resource.", "answer": "A content item pointing to a separately addressable resource.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ38", "question": "What is an embedded resource?", "answerMarkdown": "Resource content carried inline in a tool result or prompt message.", "answer": "Resource content carried inline in a tool result or prompt message.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ39", "question": "What is the safest way to expose a generated report?", "answerMarkdown": "Use a tool to generate it and a resource URI for the durable artifact.", "answer": "Use a tool to generate it and a resource URI for the durable artifact.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ40", "question": "Should SQL be a tool or resource?", "answerMarkdown": "Dynamic SQL execution is usually a tool; schema and saved reports are resources.", "answer": "Dynamic SQL execution is usually a tool; schema and saved reports are resources.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ41", "question": "Should files be resources or tools?", "answerMarkdown": "Files are natural resources; search and mutation remain tools. Tool-only host compatibility may justify fallbacks.", "answer": "Files are natural resources; search and mutation remain tools. Tool-only host compatibility may justify fallbacks.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ42", "question": "Should code review be a prompt or tool?", "answerMarkdown": "The review workflow is a prompt; data and actions may use resources and tools.", "answer": "The review workflow is a prompt; data and actions may use resources and tools.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ43", "question": "Do all hosts support prompts?", "answerMarkdown": "No.", "answer": "No.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ44", "question": "Do all hosts support resources?", "answerMarkdown": "No.", "answer": "No.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ45", "question": "Which primitive has broadest host support?", "answerMarkdown": "Tools, based on the current documented host sample.", "answer": "Tools, based on the current documented host sample.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ46", "question": "Did prompts and resources exist at launch?", "answerMarkdown": "Yes, in the 2024-11-05 specification.", "answer": "Yes, in the 2024-11-05 specification.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ47", "question": "What changed in MCP 2026?", "answerMarkdown": "Stateless requests, caching, result types, MRTR, requested subscription streams and routing metadata.", "answer": "Stateless requests, caching, result types, MRTR, requested subscription streams and routing metadata.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ48", "question": "Can MCP work without an LLM?", "answerMarkdown": "Yes; clients can list, read, get and call programmatically.", "answer": "Yes; clients can list, read, get and call programmatically.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ49", "question": "Does choosing a prompt approve tool calls?", "answerMarkdown": "No.", "answer": "No.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] }, { "id": "R6-FAQ50", "question": "What is the best design rule?", "answerMarkdown": "Use tools for operations, resources for durable data identity, prompts for explicitly selected reusable interactions, and combine them when needed.", "answer": "Use tools for operations, resources for durable data identity, prompts for explicitly selected reusable interactions, and combine them when needed.", "packageSourceIds": [ "S001", "S002", "S003", "S004" ], "sourceIds": [ "S123", "S124", "S125", "S055" ] } ] }