register_webhook

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

With no annotations, the description adds behavioral info beyond the schema: the limit of 5 webhooks and the need for an agent key. However, it does not describe error conditions (e.g., exceeding limit, invalid URL) or return values, leaving some behavioral gaps.

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: two sentences conveying purpose, constraints, and requirements. It wastes no words and is front-loaded with the key action.

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?

Given the tool's simplicity (2 parameters, no output schema), the description is fairly complete. It covers the purpose, a limit, and an authentication requirement. It could optionally mention return values, but it is adequate for a straightforward registration 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 input schema already provides 100% coverage with descriptions for both parameters. The description does not add further meaning beyond what the schema states, so a baseline score of 3 is appropriate.

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 action ('Register') and the resource ('webhook URL') with the purpose ('to receive payment notifications'). It differentiates from sibling tools like delete_webhook, list_webhooks, and test_webhook by focusing on creation.

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 provides important usage constraints: 'Max 5 webhooks per agent' and 'REQUIRES AGENT KEY'. While it doesn't explicitly state when not to use, these guidelines help the agent understand limitations and prerequisites.

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