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

Annotations already declare readOnlyHint=false, destructiveHint=false, idempotentHint=false, and openWorldHint=false, so the safety profile is covered. The description adds genuinely new context: the required `full_access` API key scope and the underlying `PATCH /webhooks/{id}` operation. The remaining gap is that it doesn't state the partial-vs-replace semantics of a PATCH for omitted fields.

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, front-loaded sentences with the operation first and the auth/endpoint metadata second. Nothing is padded.

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?

Annotations cover the mutation safety profile and there is no output schema to explain, so the baseline need is modest. However, for a mutation tool with 4 undocumented parameters and an enum-bearing `events` array, an agent still lacks guidance on what a valid update payload looks like and what a successful response returns.

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 0% and the description gives no parameter guidance at all — nothing about `events`, `status`, or `endpoint`, and nothing about `id` needing to reference an existing webhook. With four params and no schema documentation, the description should compensate and does not.

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 says 'Update a webhook,' which is a specific verb+resource but is a near-verbatim restatement of the tool name and title, adding no scope detail (which fields can be updated, what the operation affects). It does not differentiate from siblings like get_webhook, create_webhook, or delete_webhook beyond the verb itself.

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?

The 'Requires a `full_access` API key' line is a real precondition that helps an agent decide whether it can call at all, and the verb implies use on an existing webhook. But there is no guidance on when to use this versus create_webhook or delete_webhook, and no note on whether omitted fields are preserved or reset.

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