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

Annotations already cover readOnly/idempotent/destructive, but the description adds auth context beyond them: 'Pure read, no org / plan gate', which tells the agent no entitlement check blocks the call. Minor gap: the annotation title advertises 'recent dispatch metadata' that the description never mentions or explains.

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 action and immediately followed by the routing guidance. Every sentence earns its place with no preamble or filler.

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 zero-param discovery tool with no output schema, the description covers what the tool returns conceptually (valid event type values) and who needs it. It stops short of describing the return shape or whether the list is paginated/cached, but little else is required.

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?

Zero parameters with 100% schema coverage, so the baseline of 4 applies. The description correctly signals a no-argument enumeration, leaving nothing for parameter semantics to compensate for.

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 ('webhook event types the platform supports'), and the scope makes it distinguishable from list_webhooks, get_webhook, and list_webhook_deliveries. An agent immediately understands this enumerates a static vocabulary of event types.

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?

Explicitly names when to use it ('to discover valid values for the `events` array on `create_webhook` and `update_webhook`'), routing the agent to the prerequisite step before those write tools. No alternatives or exclusions are left ambiguous.

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