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

Annotations already cover the mutation/safety profile (readOnly=false, idempotent=false), and the description adds the critical behavioral fact that the response yields hmac_secret and management_token shown only once, with an instruction to store them. It omits failure behavior and what happens if verification is repeated, which matters given idempotentHint=false.

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?

Three short, front-loaded clauses with no filler; the one-shot secret warning is correctly placed before the REST cross-reference, which is secondary information.

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 two-parameter step tool with no output schema, the description supplies the step position, the required input source, and the most important return-value consequence (one-time secrets). Nothing an agent needs to invoke it 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 coverage is 100%, so both parameters are already documented, including the job_<ULID> format. The description merely restates that the challenge comes from the webhook, adding negligible meaning beyond the schema.

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 action (send back the challenge value) and its position in the flow ('Step 2 (callback mode)'), plus the REST endpoint. It is clearly distinct from create_job and retry_challenge, though it never names a sibling 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?

'Step 2 (callback mode)' implies when in the workflow it applies and that a callback/webhook has already been received, but there is no explicit when-not guidance and no routing to alternatives such as retry_challenge when the challenge is lost or expired.

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