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

Annotations cover the safety profile (readOnlyHint=false due to cancel, destructiveHint=false, idempotentHint=true), and the description adds non-annotated context: 'Free for the owning account' and the fact that cancel stops the crawl. It omits the refund/in-flight nuance, but that detail lives in the schema's cancel description, so the bar is met.

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 short sentences, front-loaded with the return contents, then the cost note, then the cancel trigger. Efficient and readable, with only minor overlap between 'Pass cancel: true' and the schema's cancel 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 usefully enumerates what a caller receives (status, pages read, discovered, queued, pages themselves), and annotations plus the schema cover safety and parameters. Pagination defaults and polling cadence are left unstated, which is a minor gap.

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 jobId, limit, and cancel are already fully documented, including the refund semantics for cancel. The description only restates the cancel usage, adding no meaning 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?

States a specific verb and resource ('Checks a crawl') and enumerates the returned fields, so an agent can distinguish it from the initiating sibling web_crawl. It stops short of naming web_crawl as the counterpart, leaving sibling differentiation partly to inference.

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 implies usage (poll a crawl started elsewhere) and gives one explicit action ('Pass cancel: true to stop it'), but never states when to use this versus web_batch_status, web_task_status, or when not to call it. Usage is implied rather than prescribed.

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