create_webhook_endpoint

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

Annotations cover the safety profile (non-readOnly, non-destructive, idempotent, open-world). The description adds value beyond them: the whsec_ signing secret is returned exactly once and must never be logged or mailed, the endpoint is active on save, and permission/tenant/agent/Live-Sandbox authorization is spelled out. This is exactly the kind of context annotations cannot carry.

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?

Dense but front-loaded: purpose first, then secret-handling warning, then authorization, then retry guidance, then docs link. The event list is duplicated between the description and the schema's event_types, which is a small waste, but every other clause 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?

An output schema exists, so return values need not be explained, yet the description still flags the one-time whsec_ secret, which is critical to handling the response correctly. Permission requirements, idempotency behavior, and environment scoping are all present, so an agent has everything needed to invoke this mutation safely.

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 the baseline is 3, but the description reinforces non-obvious semantics: which key type may set agent_id:null, that agent keys must match their own environment, that an endpoint only receives events from its environment, and the meaning of the keyword rule fields (terms, any/all, exclusions). It adds mild but real value on top of the schema.

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?

Opens with a specific verb+resource ('Create a webhook') and enumerates the exact configuration surface (name, HTTPS URL, event types, keyword rules). An agent can immediately distinguish it from update_webhook, list_webhook_endpoints, rotate_webhook_endpoint_secret, and test_webhook_endpoint in the sibling set.

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 clear preconditions and constraints: the URL requires explicit user intent, agent keys vs member keys dictate agent_id, and webhook.manage is required. It also tells the agent how to retry uncertain mutations with the same idempotency_key. It stops short of explicitly naming sibling alternatives, but the context is unambiguous.

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