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

The annotations already indicate the tool is not read-only and not destructive. The description adds valuable behavioral details: the signing secret is shown only once, and a paid plan is required. No contradictions with 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?

The description is extremely concise, using three short sentences. It leads with the core purpose, then adds the key caveat about the signing secret, and finally the plan requirement. Every sentence earns its place.

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 essential aspects: what the tool does, the one-time secret, and the paid-plan restriction. Since there is no output schema, it does not need to describe return values. It is sufficiently complete for a simple creation tool.

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 schema already provides descriptions for all three parameters (100% coverage). The description does not add extra meaning beyond the schema, so it stays at the baseline for high schema coverage.

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 clearly states the specific action ('Register a URL to receive events') and provides an example. It is easily distinguished from sibling tools like delete_webhook and list_webhooks.

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 purpose is so clear that when to use it is implied, but the description does not explicitly state when not to use alternatives like list_webhooks or delete_webhook. It does mention the paid plan requirement, which is useful context.

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