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Defined in: server/FastMCP.ts:287

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Properties

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annotations?

Defined in: server/FastMCP.ts:293 Behavioral hints for clients (MCP 2025-03-26). Forwarded verbatim in tools/list.

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auth?

Defined in: server/FastMCP.ts:315

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description

Defined in: server/FastMCP.ts:291

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disabled?

Defined in: server/FastMCP.ts:312 When true the tool is hidden from listTools and cannot be invoked via tools/call.

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input?

Defined in: server/FastMCP.ts:295 Standard Schema validator for the tool’s input arguments. Used for runtime validation.

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inputSchema?

Defined in: server/FastMCP.ts:301 Explicit JSON Schema advertised to clients as inputSchema. Overrides auto-generation from input. Use when you need JSON Schema features beyond what your validator auto-generates (e.g. examples, $comment, per-property descriptions, or custom annotations).

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name

Defined in: server/FastMCP.ts:288

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output?

Defined in: server/FastMCP.ts:303 Standard Schema validator for the tool’s return value. Validated before result conversion.

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outputSchema?

Defined in: server/FastMCP.ts:308 Explicit JSON Schema advertised to clients as outputSchema. Overrides auto-generation from output. Use when you need JSON Schema features beyond what your validator auto-generates.

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tags?

Defined in: server/FastMCP.ts:314 Arbitrary tags for server-side filtering.

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timeout?

Defined in: server/FastMCP.ts:310 Execution timeout in milliseconds. No timeout by default.

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title?

Defined in: server/FastMCP.ts:290 Human-readable display name shown in UIs. Takes precedence over name for display purposes.

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ui?

Defined in: server/FastMCP.ts:317 Apps extension — links this tool to a UI resource and controls visibility.