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

Annotations flag destructiveHint=true and idempotentHint=false, but the description explains the actual mechanism behind that destructiveness: the first call is effectively a dry-run returning a summary and confirmToken, and only a repeat call with the token mutates. That confirmation protocol is essential invocation knowledge that no annotation conveys, and it is stated explicitly.

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, no waste. The mutable-field list and the partial-update rule are front-loaded, and the destructive confirmation flow follows immediately where an agent will read it before acting.

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 nine-parameter mutation tool with no output schema, it covers the two things an agent most needs: partial-update semantics and the confirm-token protocol, including what the first call returns. It omits permission/auth requirements and failure behavior, which are minor but leave a small gap.

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 only 22%, so the description carries real weight by naming six of the nine parameters in prose (URL, name, events, active flag, expiry, retry count), leaving site, webhookId and confirmToken documented in the schema itself. It adds meaning beyond field-name mapping but no format or constraint detail (e.g., retry bounds, URI rules).

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 (changes) and resource (webhook) and enumerates the mutable fields (URL, name, events, active flag, expiry, retry count). The verb cleanly separates it from create_webhook, delete_webhook and list_webhooks, but no sibling is named explicitly, so differentiation is implicit rather than stated.

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 gives clear invocation context: 'Only the fields given change' (partial update) and the two-step protocol of first call returning a summary plus confirmToken and the second call proceeding. It never states when to prefer this over regenerate_webhook_token or test_webhook, so there are no explicit exclusions or alternatives.

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