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

Annotations only mark the operation as non-read-only and non-idempotent. The description adds useful behavioral details beyond that: it follows the Scan now path/page limits and returns either a run id or the refusal reason, which meaningfully informs an agent's expectation.

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 with no filler. The action is stated first, then the return behavior, and the reference to the Scan now button adds practical context without redundancy.

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 single-parameter tool with no output schema, the description adequately covers what the call does and what it returns. The annotations cover the safety profile, and nothing essential for invoking this tool correctly is missing.

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%: site_id is already documented as a UUID returned by list_sites. The description does not add parameter-specific details, so the baseline score of 3 is appropriate.

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 opens with a specific verb and resource: 'Start a crawl of a website'. It also gives operational scope ('same path and page limits as the Scan now button'), and this is the only start/scan action among the siblings, so it is clearly distinguished.

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 use case is clear: call this when you need to initiate a standard website crawl. It does not explicitly name alternatives or exclusion conditions, but no sibling provides an equivalent 'start scan' action, so the context is sufficient.

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