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

Annotations already declare readOnlyHint, idempotentHint and non-destructive behavior, so the safety profile is covered. The description adds genuine context beyond them: what it returns (counts and cost, never page bodies) and the required free API key, neither of which appears in 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 short sentences, front-loaded with the core action, followed by the return-content boundary and the auth requirement. Every sentence earns its place with no filler.

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?

An output schema exists, so return values need not be detailed, and the description still adds a useful return-shape note plus the API-key requirement. The remaining gap is not explaining the `jobId` parameter's origin, which an agent needs 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?

There is a single required parameter, `jobId`, with 0% schema description coverage, and the description does not explain what it is or where it comes from (presumably the output of the `crawl` tool). Since coverage is low, the description was responsible for compensating and does not.

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 specific verb+resource ("check the progress of a crawl") that is distinct from the sibling `crawl` (which starts one) and `crawlPages`. It is clear what the tool does, though it does not explicitly name or contrast against those siblings.

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?

Usage is only implied — an agent infers this is called after a crawl is initiated, but there is no explicit when-to-use or when-not-to-use guidance. The "Needs a free SnoopScan key" prerequisite is useful context but is a setup requirement rather than usage routing.

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