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

Annotations only declare destructiveHint=true, so the description carries most of the behavioral load. It discloses the meaningful persistent behavior (every future submission is POSTed to the URL) plus the underlying API route. It does not cover auth/permission requirements, retry or failure handling beyond the error_emails param, or what is returned.

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?

Two short sentences, front-loaded with the user-facing effect and followed by the API route. Slightly extraneous implementation detail ('Formstack: POST /forms/{formId}/webhooks') but no wasted prose.

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?

For an 11-parameter creation tool with full schema coverage and no output schema, the description covers the essential behavior. It does not mention what the call returns (e.g. a webhook ID needed for later updates/deletion) or any auth requirements, which would help an agent chain follow-up calls.

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 100% and each of the 11 parameters, including enums and the HMAC option, is documented in the schema itself. The description adds no parameter-level meaning, so the baseline 3 applies.

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?

States a specific verb ('Add a webhook'), the resource, and the exact effect: POSTs each new form submission to a URL. This is unambiguously distinguishable from siblings like list_webhooks or update_form without opening any schema.

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?

Usage is implied by the create semantics and the description of what the webhook does, but there is no explicit when-to-use guidance, no prerequisites (e.g. form must exist), and no statement about when NOT to create a webhook versus using list_webhooks to inspect existing ones.

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