diagnose_url

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

Annotations already declare readOnlyHint=false, openWorldHint=true, destructiveHint=false, so the agent knows this is an outward-facing operation with some side effect. The description adds real context by noting it combines Google's inspection API with a live fetch, which explains the non-read-only hint, but it does not say whether quota is consumed, whether results are cached, or what the interaction with use_cached_inspection means. Useful but incomplete beyond the annotations.

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, zero filler: the diagnostic question is front-loaded and the enumerated checks follow immediately. Every clause carries information an agent can use to decide whether to call it.

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 four-parameter diagnostic tool with no output schema, the description does the important work of telling the agent what signals come back (redirects, status, noindex, canonicals, robots rule, thin content), so the return value is not a mystery. What is missing is the cost/rate-limit dimension of running a fresh inspection versus a cached one.

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% and the schema itself explains site formats, user_agent options, and the cached-inspection flag well. The description's reference to "a live fetch" and "Google's inspection" loosely maps to user_agent and use_cached_inspection but adds no format or defaulting detail beyond the schema. Baseline 3 applies.

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?

Opens with a specific diagnostic question ("Why is this URL (not) indexed?") and enumerates the concrete checks it performs: redirect chain, status, noindex, canonicals, robots.txt rule, thin content. That verb-plus-resource framing clearly separates it from single-purpose siblings like robots_txt_check or check_redirects, since this one aggregates them. It stops short of naming a sibling explicitly, which is why it is a 4 rather than a 5.

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 "Why is this URL (not) indexed?" framing implies the use case: per-URL indexing diagnosis. But nothing states when to prefer this over inspect_url, check_redirects, or robots_txt_check, all of which appear in the sibling list and overlap with pieces of this tool. Usage is inferable rather than guided.

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