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

The annotations only declare the generic profile (not read-only, open-world, non-idempotent, non-destructive), while the description adds the operationally important facts: no API key or account needed, the pending capture is stored before the call returns, and the write is public so secrets/credentials/personal data must not be sent. The notify_url delivery contract — one signal with a result URL, not the captured payload — is behavior an agent could not infer from 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?

Front-loaded with the core definition, then constraints and the security caveat; every sentence is doing work except the reference to 'update_url', a parameter that does not exist in this tool's schema and reads as leftover boilerplate from a sibling tool, which can send an agent looking for a nonexistent field.

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, and timing, callback behavior, and safety are all covered. The gaps are minor but real: capture lifetime/expiry is unspecified and the description never points at read_webhook_capture as the way to fetch the recorded request.

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% and the single optional parameter is already documented, but the description adds real meaning beyond the schema: the callback carries a result URL and explicitly does not contain the captured request, and the public-readability warning constrains what an agent should ever send. This is meaningful value over an already-complete 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?

The first sentence states a specific verb and resource — create a throwaway URL that records the next inbound HTTP request with headers and body — and the scope (one request only) distinguishes it from read_webhook_capture and schedule_webhook without requiring the schema. An agent can tell immediately what is produced.

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 gives clear when-to-use guidance: inspecting what a provider/form/third party actually transmits rather than trusting docs, and proving an integration fired. It does not, however, explicitly name the follow-up tool (read_webhook_capture) that retrieves the capture, nor state when not to use it versus schedule_webhook for repeated captures.

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