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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint false, and openWorldHint false, while the description adds retention (30 days), payload omission, auth scope, ordering, and returned status/attempt fields. It also reinforces no mutation with 'Reading changes nothing', though it does not discuss pagination or rate limits.

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 short sentences front-load the purpose and then add operational constraints with no filler. 'Reading changes nothing' is slightly duplicative of readOnlyHint but is brief and reinforces the safety profile.

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 a single required id, full schema coverage, and an output schema, the definition gives enough information to invoke the tool correctly. Minor omission: it does not describe pagination or a result limit for 'most recent' deliveries.

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% and the sole parameter 'id' is documented in the schema as the webhook endpoint's id. The description confirms the endpoint scope but adds no syntax or format details beyond what the schema already provides, so the 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 specific verb ('List') and resource ('deliveries to a webhook endpoint'), plus ordering ('newest first') and returned fields ('attempt count' and 'last HTTP status code'). This clearly distinguishes it from sibling tools like list_webhook_endpoints, which lists endpoints rather than delivery attempts.

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?

The description makes the inspection context clear and states the auth prerequisite: only the account owner's API keys and connected apps can read webhooks. It does not explicitly name alternatives such as get_webhook_endpoint or send_webhook_test, so when-not guidance is absent, but the use case is not ambiguous.

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