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

Annotations already declare destructiveHint=true and idempotentHint=true, so the safety profile is covered. The description still adds meaningful context beyond them: the operation is irreversible and specifically destroys the delivery history, plus it mandates user confirmation before proceeding — exactly the 'what gets destroyed' detail the rubric rewards.

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?

Three short clauses, front-loaded with the destructive action and its scope, then the irreversible/confirm caveat, then the alternative. Every sentence earns its place with no filler.

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?

Output schema exists so return values need no explanation, and annotations already cover the safety/idempotency profile. The description supplies the remaining critical facts — irreversibility, scope of deletion, confirmation requirement, and the pause alternative — leaving nothing an agent needs missing.

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 both parameters (endpoint_id, idempotency_key) are fully documented in the schema, including the idempotency retry semantics. The description adds no parameter-level meaning beyond the schema, 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?

Specific verb+resource ("Delete a webhook endpoint") immediately says what happens, and it further names the secondary effect ("and its delivery history"). It also routes the agent away from destructive intent when pausing is the actual goal, distinguishing it from siblings like update_webhook_endpoint.

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?

Explicit when-to-use (removing an endpoint and its history), explicit when-not-to-use with the exact alternative ("To pause deliveries use update_webhook_endpoint with is_active=false"), and a required precondition ("confirm with the user"). Nothing is left to inference.

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