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

Annotations already declare destructiveHint=true, idempotentHint=true, and readOnlyHint=false, so the safety profile is fully covered by structured data. The description adds nothing beyond that — it does not say whether deletion is permanent, what happens to in-flight deliveries, or whether re-creating the id is possible.

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?

A single front-loaded sentence with zero filler. However, for a destructive operation the extreme brevity arguably omits warranted caveats rather than representing true economy of expression.

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 no explanation, and a one-parameter delete is structurally simple. What is missing is any statement of consequence — that deletion is irreversible and stops webhook deliveries — which matters for a destructive tool.

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 the single 'id' parameter is documented with its 'wh_…' format, so the schema carries the full burden. The description's 'by id' phrase adds no syntax or format detail beyond what the schema already provides, making the baseline 3 correct.

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 ('Delete a webhook endpoint') plus the lookup key ('by id'), which is unambiguous and clearly distinct from siblings like create_webhook and list_webhooks. It stops short of explicitly contrasting itself with those siblings, so it lands at 4 rather than 5.

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?

There is no guidance on when to delete versus simply disabling a webhook, no warning that this halts event delivery, and no mention of any alternative tool. The reader must infer all usage context from the verb alone.

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