MCP Public APIs

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

No annotations provided, so description carries full disclosure burden. It mentions external GitHub dependency and return value format ('summary of how many APIs were loaded'), but omits mutation semantics (does this overwrite existing index atomically?), error scenarios, and duration expectations.

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?

Three sentences with zero redundancy: action definition, usage trigger, and return value description. Front-loaded with the core operation and efficiently structured.

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?

Appropriate for a zero-parameter maintenance tool with output schema. Covers purpose, trigger condition, and return summary. Lacks only error handling documentation and explicit destruction warnings, which would be required for a 5 without annotations.

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?

Zero parameters establishes baseline 4 per scoring guidelines. Empty object schema with 100% coverage is trivially complete, requiring no additional parameter semantics from description.

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?

Specific verb-resource combination ('Re-download...README', 'rebuild the index') clearly distinguishes from sibling list_categories. Identifies exact source (public-apis GitHub) and target operation.

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?

Explicitly states trigger condition 'Use this if the index seems stale or empty', providing clear when-to-use guidance. Lacks explicit naming of list_categories as the alternative for normal querying, but the context is clear.

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