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

Goes well beyond the readOnly/idempotent annotations: results is null until the scan completes, results_unavailable signals an unreadable stored result set, an unreadable robots.txt is reported as unknown rather than absent, and lists are capped at 25 entries with totals supplied. These are exactly the edge cases an agent needs to interpret a response correctly.

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 core purpose is front-loaded, but the body is one long run-on sentence with heavy nested parentheticals that is hard to scan. The 'in the Yellowhead app' caveat is stated twice, once for results_unavailable and once for per-URL results, which is redundant.

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?

No output schema exists, so the description carries the full burden of explaining return values, and it does so comprehensively: scan metadata, page counts by category, run summary contents, null semantics, and failure flags. Nothing material is missing for an agent to call and interpret this tool.

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 one parameter with 0% schema description coverage, so the schema contributes nothing beyond the uuid format. The description says 'by id' and thus implies the id identifies a specific scan, but it does not say where to obtain that id (presumably list_crawlability_scans), leaving the parameter only partially explained.

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: 'Returns one Crawlability Scan by id'. The singular 'one ... by id' scope cleanly distinguishes it from the sibling list_crawlability_scans and from the other get_* scan tools, which cover different scan types.

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 'by id' framing implies this is the single-record lookup and the list tool is the way to enumerate, but the description never states when to use this versus list_crawlability_scans or what to do if the id is unknown. 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.