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

Annotations only tell the agent this is a non-read-only, non-destructive, non-idempotent, closed-world write. The description adds real context beyond that: deliveries are signed with an X-Staalptkram-Signature header, an empty url deletes the registration, and an API key is required. It does not disclose whether an existing webhook is overwritten or what rate limits apply, but it is well ahead of the annotation baseline.

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 core action, followed by the header detail, the removal case, and the auth requirement. No filler or restatement of the title.

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?

With no output schema and thin annotations, the description still conveys the operation, the payload signing, the deletion semantics, and the auth requirement. The remaining gap is the undocumented `secret` parameter and what happens when a webhook is re-registered, which an agent would need to infer.

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 carry both parameters. It adds genuine meaning for url (https only, empty string means remove) but never mentions the optional `secret` parameter, leaving it completely undocumented in both schema and description.

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 a specific verb (register/remove) and resource (an https webhook URL) and explains the delivery mechanism (events as signed POSTs). It also covers the inverse operation via an empty url, so an agent knows exactly what the tool does and what mutating it means.

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?

It states the trigger condition (register a URL to receive events) and the removal path (pass an empty url), and notes the API-key prerequisite. No sibling tool competes for this job, so there is no alternative to route to — a clear context signal without explicit exclusions.

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