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

The description goes well beyond the annotations (destructiveHint=true, idempotentHint=false): it discloses the retry schedule (1m/5m/30m/2h/12h then dead-letter), that every call mints a fresh secret shown once and invalidates the old one, that a same-key retry is refused with `conflict` rather than replayed, the exact signature header format, and an immediate `webhook.test` event. It also enumerates every refusal reason. Minor gap: it doesn't restate that the change is destructive (replacing the existing webhook/secret) in so many words, though 'the old one stops verifying' implies it.

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?

Front-loaded with purpose and the API-key prerequisite before the dense detail, and nearly every clause carries operational value (signature format, retries, refusal reasons). It is a single very dense block with heavy parentheticals, which costs some readability, but there is little padding to cut.

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 still covers the return contract (the minted `webhook_secret` shown once, the test event) and the failure surface in detail. For a mutation tool with these annotations, an agent has everything needed to call it correctly and interpret the result.

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 the baseline is 3, but the description adds real meaning: `url: null` stops pushing, and the per-reason rejection vocabulary (`malformed`, `not_https`, `our_infrastructure`, `localhost`, `private_address`) tells the caller what values will fail. For idempotency_key it reinforces the 24h window and the secret-conflict rule.

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 opening states a concrete verb and resource: it configures the push side of the event stream that POSTs every profile event to `url`. It explicitly contrasts with the pull alternative (`events()`, `docs('receive-events')`), so an agent can distinguish it from the polling siblings without opening a schema.

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?

It states the prerequisite (needs your API key), the alternative (poll events() instead), and the off-switch (`url: null` stops pushing), plus a pointer to docs('receive-events') when the caller has no server. When-to-use and when-to-use-something-else are both explicit.

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