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

With zero annotations, the description carries the burden and does disclose the destructive scope: deliveries stop for this API key, the registration is deleted, and the signing secret goes with it. It does not state whether the operation is reversible without re-registering, or what happens if no webhook exists, 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?

Three short sentences, front-loaded with the action and consequence, then the usage condition, then the alternative. Nothing is redundant.

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?

A zero-parameter, no-output-schema tool is largely covered here: what it does, side effects, and the sibling to use instead. Missing only failure/idempotency behavior (e.g., calling when no webhook is registered), a minor gap for a destructive call with no annotations.

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?

The tool takes no parameters, so the baseline applies. The description usefully clarifies the implicit scoping — the webhook belongs to 'this API key' — which is the only semantic detail an agent needs.

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 and resource — stop deliveries and delete a webhook registration — plus the notable detail that the signing secret is removed. This clearly distinguishes it from the sibling set_webhook, which configures rather than removes.

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?

Gives an explicit when-to-use condition (the receiving endpoint is being retired) and names the alternative for the adjacent intent (change URL or filters -> set_webhook). No inference needed to route between the two.

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