FastMCP Development Assistant

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already provide readOnlyHint=true (safe read operation) and openWorldHint=true (accesses external data), so the description doesn't need to repeat these. It adds value by specifying the exact resource (README file) and source (FastMCP GitHub repository), but doesn't disclose additional behavioral traits like rate limits, authentication needs, or response format details beyond what annotations cover.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, efficient sentence in Japanese that directly states what the tool does without any wasted words. It's front-loaded with the core action and resource, making it easy to parse quickly.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's simplicity (0 parameters, read-only operation with annotations), the description is adequate but minimal. It lacks output schema information (not provided) and doesn't explain return values or potential errors, which could be helpful for an agent. However, for a basic fetch tool with good annotations, it meets minimum viability.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

There are 0 parameters, so no parameter semantics are needed. The description appropriately focuses on the tool's purpose without unnecessary parameter details, aligning with the high schema description coverage (100%) and absence of parameters.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the action ('fetch'/'取得します') and resource ('README file from FastMCP GitHub repository'/'FastMCPのGitHubリポジトリからREADMEファイル'), making the purpose specific and understandable. However, it doesn't explicitly differentiate from sibling tools like 'fetch-fastmcp-versions' or 'fetch-mcp-architecture-doc', which also fetch from similar sources but different resources.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides no guidance on when to use this tool versus alternatives. It doesn't mention sibling tools like 'fetch-fastmcp-versions' (for version data) or 'fetch-mcp-architecture-doc' (for architecture documentation), leaving the agent to infer usage based on resource names alone without explicit context or exclusions.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.