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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds value by scoping what is returned and by explicitly deferring signature/retry/ordering semantics to the guide, but says nothing about error behavior for an unknown event name.

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 compact sentence that front-loads the return contents and ends with the pointer to the guide. No filler, though the parenthetical example duplicates the schema's own example.

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?

There is no output schema, so the description must characterize the return value, and it does so at a high level (timing, payload fields, example). For a one-parameter read-only lookup this is close to sufficient; only failure behavior for an invalid event name is unaddressed.

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 single 'event' parameter is documented with the same example the description uses, so the description adds no meaning beyond the schema. Baseline 3 applies when the schema does the heavy lifting.

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?

The description names the resource (one webhook event) and enumerates what the caller gets back: send timing, payload fields, and an example. It implicitly contrasts with list_webhooks by scoping to a single event, though it never states that contrast explicitly.

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?

Usage is only implied by the singular scope. It does route the agent elsewhere for related concerns (signature, retry and ordering rules live in the guide's webhooks section), which is a useful boundary, but there is no explicit when-to-use versus list_webhooks or get_guide_section.

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