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

Annotations declare destructiveHint=true and idempotentHint=true, so the core risk profile is covered. The description adds value the annotations do not carry: required key tier (Light/Pro/internal), the exact header form, and that trial keys receive 403. It does not state whether the delete is immediate or recoverable, which is arguably already implied by the destructive hint.

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?

Front-loaded with the action, then auth requirements, all in compact clauses. The trailing 'Informational market data only; not investment advice' is boilerplate that does not help an agent invoke the tool and slightly dilutes the definition.

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 single-parameter destructive tool with full annotation coverage and no output schema, the description supplies the missing pieces an agent needs: credential requirement, failure mode for trial keys, and id format. Only the post-deletion effect (irreversible, effects on delivery) is left implicit.

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 0% with one required parameter, so the description must compensate. It supplies the 'wh_...' id prefix, which meaningfully identifies the expected value shape, though it omits where the id comes from. That is a solid but not exhaustive compensation.

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 ... webhook alert hooks') with the id format ('wh_...') named, which is more than the name alone conveys. It doesn't explicitly differentiate itself from siblings like list_alert_webhooks or register_alert_webhook, but the action is unambiguous.

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?

Usage is implied by the verb and the stated authorization requirement, which is genuinely useful context. However, it never says when to prefer this over alternatives, nor where to obtain the id (e.g., via list_alert_webhooks), so the agent must infer the workflow.

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