URL inspection

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

Annotations already declare readOnly and idempotent, but the description adds substantive operational context the annotations cannot convey: server-side concurrency (2 requests at a time), batch cap of 20, and quota of roughly 600/min and 2000/day per property with an explicit 'keep batches small' instruction. That is exactly the value-add expected beyond structured hints.

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?

Output fields are front-loaded, then invocation modes, then limits. No filler sentences; even the quota sentence carries actionable guidance ('keep batches small'). It is dense but every clause earns its place.

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 compensates by enumerating the return payload (verdict, coverage, canonical chosen vs declared, mobile usability, rich results). Combined with the quotas, batch behavior and property constraint, an agent has everything needed to call it correctly.

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 baseline is 3, but the description adds the cross-parameter constraint that every inspected URL must belong to the named property — a semantic rule absent from the individual parameter docs. It also restates the batch size limit, which the schema already caps via maxItems, so the added value is real but partial.

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 (inspect) plus resource (URLs) with an explicit enumeration of what is returned: verdict, coverage, robots.txt state, last crawl, canonical mismatch, mobile usability, rich results. An agent can immediately distinguish this from the sibling aggregate tools (query, opportunities) without opening a 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?

Clearly states how to choose between single (url) and batch (urls) invocation and the constraint that URLs must belong to the property; the schema even points to list-properties for property discovery. It never explicitly names a sibling as the alternative for aggregate/index-wide questions, so it falls short of full when-not routing.

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