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

Annotations declare destructiveHint=false and idempotentHint=true; the description earns credit by explaining WHY it isn't destructive — alerts remain retrievable via hl_poll_alerts. It doesn't address what happens when no webhook is configured (relevant to idempotency), which would have capped it at 5.

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?

One sentence, effect first, caveat second. Nothing is superfluous and nothing essential is buried.

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?

With an output schema present, no parameters, and annotations covering safety and idempotency, the only real behavioral question is what happens to the alerts — which the description answers. Slightly more on the post-delete state (e.g. webhook cleared vs. pending delivery) would make it fully complete.

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?

Zero parameters, so the baseline is 4. The phrase 'this key's' usefully signals that the target webhook is scoped implicitly by the authenticated key rather than by an ID argument.

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 ('Stop POSTing') and resource (this key's webhook) with the precise effect, and distinguishes it from hl_delete_alert by clarifying that alerts themselves are not deleted. An agent can tell exactly what stops happening 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?

The parenthetical points to hl_poll_alerts as the alternative delivery mechanism, which implicitly answers 'when do I use this vs. keep the webhook'. It lacks an explicit 'use when the user wants to stop push delivery' framing, but the direction is clear.

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