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

Annotations already declare non-read-only, non-idempotent, non-destructive, open-world behavior; the description reinforces this by saying the call fires one delivery immediately and cannot be batched. It adds the meaningful operational constraint that the endpoint must be enabled, which the annotations do not express. It does not say what happens on failure or whether the attempt is retried.

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?

A single sentence plus a precondition clause; the action and its constraints are front-loaded with no filler. Every clause carries information an 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 two-parameter mutation with no output schema and clear annotations, the definition covers the action, the single-shot semantics, and the endpoint precondition. The remaining gap is the result of the call (no delivery identifier or error behavior described), which matters slightly more because no output schema exists.

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?

At 50% schema coverage, webhook_event_id is documented in-schema as coming from list_webhook_deliveries, while webhook_endpoint_id has no description anywhere. The description implies the endpoint is an existing, enabled one but does not state that both IDs are required or how they pair up. Coverage is adequate but the description does not compensate for the undocumented parameter.

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-resource pair: re-post one past webhook event to an endpoint. The qualifiers 'once' and 'now' scope it to a single immediate redelivery, which cleanly separates it from inspection tools like list_webhook_deliveries and from endpoint CRUD siblings.

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 an explicit precondition ('The endpoint must be on') and a scope limitation ('once', single event), and points at list_webhook_deliveries as the way to confirm the attempt. It stops short of naming when a redelivery is appropriate versus not (for example, after disabling/re-enabling), but there is no sibling that competes for the same job.

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