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

Goes well beyond the annotations: annotations only declare destructiveHint=true and non-idempotent, while the description discloses that the old secret is invalidated immediately, the replacement is returned exactly once, the caller must store it and update its receiver, inactive/unknown IDs yield not_found, and there are no automatic retries. These are critical operational facts an agent cannot get from the schema or hints.

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?

Four tightly written sentences, front-loaded with the action and its destructive effect, followed by the permission requirement, the one-time return, and error behavior. No filler and every clause carries actionable 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 destructive, non-idempotent mutation with no output schema and only one parameter, the description covers everything an agent needs: what is destroyed, the permission required, the one-time nature of the return value, storage guidance, and failure semantics. Nothing material is omitted.

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?

The single parameter (webhookId, uuid) is not described at 0% schema coverage, but its meaning is self-evident from context ('an active project webhook signing secret' identifies which webhook is being targeted). The description adds no format, constraint, or lookup guidance beyond what the parameter name implies, so this is the minimum-acceptable baseline.

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 and resource ('Rotate an active project webhook signing secret') with an explicit scope qualifier ('active project') and effect ('invalidating the previous secret immediately'). It is clearly distinguishable from webhook siblings like create_webhook, delete_webhook, and list_webhooks without opening any 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?

Gives concrete context for use: the subscription must be active, and the caller needs webhooks.write. It also tells the agent what happens in the negative case ('Inactive or unknown subscriptions return not_found'). It stops short of naming an alternative tool or a when-not-to-use case, so it is clear on context but not fully explicit on alternatives.

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