create_webhook

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

With no annotations provided, the description carries full responsibility for behavioral disclosure. It reveals critical behaviors: the signing secret is returned only once and must be stored, valid event names are listed, and there is a 10-webhook limit. This is substantial transparency for a mutation tool.

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 compact: one sentence for purpose, one for the secret, one list for events, and one for constraints. Every sentence carries information, with no filler. It is well-structured and easy to parse.

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?

Despite having no output schema, the description provides essential context: what the tool does, the event catalog, the secret return behavior, and resource limits. It covers the key aspects needed to invoke the tool successfully, especially given the schema already documents parameters.

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 coverage is 100%, so baseline is 3. The description adds value by enumerating the valid event names for the 'events' parameter and clarifying the 'url' must be an HTTPS endpoint (though schema already says HTTPS). It also mentions the scope caveat via register_credit_threshold, further enriching parameter meaning.

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 opens with 'Register a webhook endpoint for account events,' which is a specific verb+resource pair that clearly states the tool's function. It also distinguishes itself from siblings like list_webhooks and test_webhook by mentioning the event catalog and the alternative register_credit_threshold for credit-specific events.

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 explicitly provides usage context: when to use the tool (for account events), alternatives (register_credit_threshold for credit events), and constraints (max 10 webhooks, requires a developer key). This gives clear guidance on selection and prerequisites.

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