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

Annotations declare openWorldHint=true and destructiveHint=false, so the agent already knows an external side effect occurs without mutation of stored state. The description adds meaningful context beyond that: the test emits a simulated event payload and returns a deliveryId intended for correlation with endpoint logs. It omits whether the call counts against delivery quotas or is rate-limited, which keeps it short of a 5.

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?

Two tight sentences, front-loaded with the action and its purpose; the return-value note is compressed into one clause. Nothing is padded or repeated.

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?

An output schema exists, so return-value detail is not required, yet the description still hints at the deliveryId correlation use case. For a two-parameter tool with full schema coverage and annotations covering the safety profile, an agent has everything needed to invoke it correctly.

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 description coverage is 100%, so both parameters (id, event) are already fully documented, and the description adds no syntax, format, or default details beyond them. Baseline 3 is appropriate when the schema carries the parameter burden.

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?

Specific verb+resource+outcome: it sends a test event payload to a webhook and states exactly what the test verifies (endpoint reachability and signature verification). This is clearly distinguishable from webhook_set/get/list/delete siblings, which configure or read webhooks rather than probing a live endpoint.

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 gives clear context for use – verifying an endpoint is reachable and its signature verification works – which is exactly the situation that selects this tool. It names no explicit exclusions or alternatives, but the sibling set offers no real substitute, so the gap is minor.

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