Diagnose a page

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

The annotations only mark the tool read-only and open-world, so the description carries the behavioral burden and does it thoroughly. It discloses that the tool is slow, returns a job ID, requires polling via check_status, makes no extra API calls, filters one-off failures, and that savings are non-additive with median/spread reported. This is far more than the annotations alone provide.

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?

Every sentence earns its place: purpose, reliability rule, ranking rationale, overlap warning, and job-ID workflow are all distinct and valuable. The description is dense but appropriately scoped for a tool with no output schema, and it front-loads the core purpose before caveats.

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?

With no output schema, the description takes responsibility for explaining both output semantics and how to obtain results. It explains what is returned (ranked failures, savings with median/spread), how to collect them (check_status), and important interpretation rules (use order not sum). Nothing essential for correct calling and interpretation appears missing.

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 description coverage is 100%, so the baseline is 3 even without parameter details in the description. The description does add context tying 'runs' to distinct analyses and repeated failures, but most parameter meaning is already in the schema, so no additional compensation is needed.

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 states a clear verb and resource: it reports what is failing on a page and ranks fixes by value, using Google's audit findings. It is unmistakably about page diagnosis, though it does not explicitly contrast itself with the sibling 'diagnose' or other report tools, so it stops short of full sibling differentiation.

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 gives strong usage context: it only reports faults repeated in every run, ranks by what actually affects the performance score, warns that savings overlap, and explains the job-ID flow with check_status. It does not explicitly state when to prefer this over siblings like 'report' or 'compare', but the behavioral conditions are clear enough for most selection decisions.

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