headers_check

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

Discloses payment requirement and behavior (402 if unpaid). No annotations, so description carries full burden. Does not mention any side effects or whether URL is fetched publicly, but overall transparent.

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?

Two sentences, no fluff. First sentence states core function; second adds critical payment context. Highly efficient.

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?

Covers purpose, parameter, and payment. Lacks example output or detailed list of headers, but for a single-parameter tool this is adequate. Could include a note about required authentication or rate limits, but not essential.

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?

Schema already documents 'url' parameter well. Description adds value by indicating HTTP method (POST) and that the URL is the payload. With 100% schema coverage, baseline is 3, but extra context merits a 4.

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?

Clearly states the tool fetches a URL and analyzes HTTP security headers, outputting present/missing and a score. Differentiates from siblings like seo_audit or robots_check which focus on other aspects.

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 notes paid service with 402 for unpaid, and prerequisite of funded wallet. No explicit when-not-to-use, but sibling tools are distinct enough to avoid confusion.

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