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

The annotations already declare readOnlyHint=false, destructiveHint=false, and non-idempotence. The description adds critical operational behavior: the signing secret is returned once and must be handed to a human immediately, and the URL must be HTTPS on a public address. These are high-value disclosures beyond the structured annotations.

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 tight sentences with no waste. The one-time secret warning and URL validation are front-loaded and easy for an agent to act on.

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?

The description covers the most dangerous behavioral detail (one-time secret) and URL validation, which is important given the lack of an output schema. However, with 0% schema description coverage it omits what the events array should contain and what name does, leaving the creation payload under-specified.

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 0%, so the description must compensate for all three parameters. It clarifies the url constraint (HTTPS, public address) but says nothing about the required events array or the optional name parameter, leaving most parameter semantics undocumented.

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 states a specific verb and resource: registering an HTTPS endpoint to receive events. It clearly distinguishes creation from reading or deletion, but it does not explicitly differentiate itself from siblings like update_webhook, rotate_webhook_secret, or delete_webhook.

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 implied by 'Register an HTTPS endpoint to receive events' and the URL constraints, but the description never states when to choose this tool over update_webhook, rotate_webhook_secret, or test_webhook. No alternatives or exclusions are named.

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