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

Annotations already cover read-only, idempotent, open-world, non-destructive behavior, and the description adds substantial return-shape detail that annotations can't: grade range A+ to F, rubric, per-manifest errors vs warnings, steps covered, callable capabilities, and next steps. It also notes the externally visible report page and badge URL, extra context beyond structured fields.

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?

Front-loaded with purpose, input, and output; dense but well ordered. The final sentence about the /check/ page and /badge/ SVG is somewhat tangential to invoking the tool, though it does hint at side effects/stability of the report.

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?

No output schema exists, so the description carries the return burden and does so thoroughly — grade, rubric, errors, warnings, coverage, callable capabilities, and next steps. Combined with the input explanation, an agent has everything needed to call it and interpret results.

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?

With 0% schema description coverage, the description must carry parameter meaning, and it does: origin is framed as a public origin/domain, and id is explicitly optional and scoped to a single manifest. It enumerates the same ids as the schema enum without explaining each manifest type, leaving minor ambiguity.

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 opens with a specific verb and resource ("Validate a public origin's agent-facing manifests") plus an outcome ("grade its agentic-web readiness"), which cleanly separates it from generic siblings like get, probe, or search. An agent can identify the task without opening the schema.

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?

It explains the required input (origin) and clarifies the optional id's role — "to check one manifest only" — rather than all manifests. It doesn't name alternative sibling tools or state exclusions, but usage context is clear enough to select the tool confidently.

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