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

No annotations are provided, so the description carries the full burden, and it delivers the single most important behavioral fact: `secret` is returned once and must be stored as COINVELLO_WEBHOOK_SECRET. It also discloses URL scheme rules (HTTPS for live, http://localhost for test), which is real operational context. Gaps remain around auth/permissions, idempotency, and what happens on duplicate URLs.

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 action, then the critical secret caveat, then constraints. Four compact sentences with no filler, though the phrasing is dense and could group the URL rules more cleanly.

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 a 5-parameter mutation with a nested `metadata` object, no annotations, and no output schema, the description covers the highest-risk items (one-time secret, URL scheme) but leaves a third of the parameters and the full response shape undocumented. Adequate but with real gaps.

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 only 40%, so the description should compensate more than it does. It explains `events` (`["*"]` or a list of event types) and the `url` scheme rules well, but `enabled`, `metadata`, and `description` get no semantic treatment in the description at all.

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 and resource ("Register a webhook endpoint") that maps unambiguously to a single action, and it is trivially distinguishable from siblings like verify_webhook_signature or create_checkout_session.

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?

Implies when to use it (registering an endpoint for testing vs live, choosing event lists) but never names an alternative tool or states when not to use this one. The live-URL vs test-URL constraint is useful context, but there is no explicit routing guidance among the many create_* siblings.

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