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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the safety profile is known. The description adds one genuine behavioral rule (test is repo-only), but never says which action is destructive, that delete is irreversible, or what permissions are needed. With annotations carrying the safety burden, this is adequate but thin.

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 sentences, front-loaded with the resource and scope model before the exception rule. Nothing is redundant with the schema and every sentence carries a constraint the agent needs.

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 15-parameter, six-action mutation tool with no output schema, the description omits what each action returns, what create/update actually change, and that delete removes the hook permanently. The schema compensates for parameter detail, but the action-level behavior remains underspecified.

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%, so all 15 parameters are already documented in the schema, including action/scope enums and per-action requirements. The description only reinforces the scope enum semantics and the test restriction, adding marginal value beyond the structured fields. Baseline 3 applies.

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 concrete resource ('webhooks') and scoping model ('repository or organization scope'), which no sibling tool covers. It doesn't spell out the full action set in the prose, but the title-less definition is still immediately distinguishable from repos, issues, or ci.

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?

Offers real routing guidance between scope='repo' and scope='org', and explicitly warns that the 'test' action is unavailable for org webhooks. However, there is no sibling alternative to steer away from, so this is parameter-level guidance rather than true when-to-use guidance; an agent still infers that this is the only webhook tool.

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