Add tool annotations

[mattt]

See https://modelcontextprotocol.io/specification/2025-06-18/schema#toolannotations

This PR adds tool annotations based on REST conventions for HTTP verbs in the OpenAPI schema.

This is enabled by default, and can be disabled with the --no-annotations option.

[Copilot]

Pull Request Overview

This PR adds MCP (Model Context Protocol) tool annotations to HTTP tools generated from OpenAPI specifications. The annotations provide REST-aware metadata including title, read-only hints, idempotent hints, and destructive hints based on HTTP verb conventions. A new --no-annotations command line flag allows users to disable this feature.

• Adds REST-aware MCP ToolAnnotations based on HTTP verb conventions (GET=readonly/idempotent, POST=destructive/non-idempotent, etc.)
• Introduces configurable options pattern with WithoutAnnotations() for disabling annotations
• Adds --no-annotations CLI flag to provide user control over annotation generation

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
internal/openapi.go	Adds ToolAnnotations generation logic with options pattern and REST convention mapping
cmd/emcee/main.go	Adds CLI flag and option passing to disable annotations

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[Copilot]

[nitpick] The variable destructiveTrue is defined but only used for POST, PUT, PATCH, and DELETE cases. Consider defining it only where needed or use a literal true directly in the assignments to reduce unnecessary variable declarations.

Suggested change

destructiveTrue := true