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

Goes beyond annotations with concrete behavioral facts: no saved tab is created, a blocked target returns HTTP 502 with target_blocked, and the report does not certify security or accessibility. These error and scope details are not derivable from readOnlyHint/openWorldHint/destructiveHint. It still doesn't clarify why readOnlyHint=false despite no saved tab (e.g. quota or audit record writes).

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?

The behavioral and error details are front-loaded and useful, but the trailing sentences ('This is the product for agents. The free alternative: a person signs in with an account to get the trial.') are marketing-flavored and loosely related to tool selection, adding noise to an otherwise compact description.

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 carries the burden of explaining returns and does so reasonably ('evidence, limits and suggested changes') plus a documented failure mode (502/target_blocked). Scope disclaimers round it out, though return shape specifics remain thin.

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 all three parameters (url, guest_token, compare_with) are already documented in the schema. The description adds no syntax or format detail beyond that, making 3 the appropriate baseline.

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 gives a concrete verb ('Check') and enumerates the audited resources (search metadata, crawl access, structured data, discovery files). It distinguishes itself from persistence-oriented siblings by stating it works 'without creating a saved tab', though it never names the closest sibling audit_site explicitly.

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?

'This is the product for agents. The free alternative: a person signs in with an account to get the trial' addresses audience/eligibility but not when to choose this over audit_site or run_tab. The 'without creating a saved tab' clause implies a no-persistence use case, but no explicit when/when-not guidance or named alternatives are provided.

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