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

Annotations already cover destructiveHint and idempotentHint, so the description's added value is the consequence clause — deliveries stop permanently — and the reversibility contrast with pausing. It goes slightly beyond the annotations rather than repeating them. It does not state whether deletion is soft or hard recoverable beyond the word "permanently", nor any permission requirement.

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 sentences; the destructive effect is front-loaded and the alternative follows immediately. 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?

For a two-required-parameter delete with full schema coverage and annotations carrying the safety profile, the description covers effect, permanence, and the safer alternative. No output schema exists, but a delete's return is low-stakes and largely implied; a note on whether the deletion is reversible or requires confirmation would close the remaining gap.

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 each parameter (site_id, webhook_id, user_goal) is documented with provenance hints like "from list_webhooks". The description adds no parameter detail beyond the schema, so the baseline 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?

Names a specific verb and resource ("Permanently delete a ... webhook") plus the scope ("site-wide"), and states the resulting effect that nothing is sent to the address. An agent can distinguish this from update_webhook or create_webhook without opening the schema.

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?

Explicitly routes the alternative case: "To pause it instead, use update_webhook with is_active false." That names the sibling tool and even the parameter value that selects the non-destructive path.

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