Check configuration

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

Adds real context beyond the readOnlyHint/openWorldHint annotations: it discloses the three specific probes performed and states the key is not disclosed, which is a security-relevant trait. It does not mention latency or how results are structured, so not a 5.

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 the triggering condition ('Use first when anything looks wrong') followed by what it reports. Two dense sentences with little waste, though the parenthetical enumeration slightly repeats the preceding clause.

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?

For a zero-param, read-only diagnostic with no output schema, the description supplies everything an agent needs: when to call it, what it verifies, and that it does not leak the key.

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, so the baseline is 4; the description correctly implies no inputs are needed and does not misrepresent any parameter behavior.

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?

States a specific diagnostic purpose with a clear verb (check) and enumerates what it reports: key present, PageSpeed reachable, Chrome UX Report permitted. It is clearly separable from siblings like analyse_page or explain_lcp because it is the pre-flight config check.

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 says 'Use first when anything looks wrong' and frames the goal as telling a configuration problem apart from a slow or failing page 'before committing to a full check' — a named alternative and a condition that selects it.

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