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

Annotations already declare destructiveHint=true, so the repeated 'This is destructive' adds no credit. The genuinely useful addition is 'requires approval by default,' which discloses a workflow/authorization prerequisite not captured by the annotations or schema hint. It stops short of explaining what actually gets destroyed, but with annotations covering the safety profile this is above baseline.

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 with the usage trigger front-loaded and no filler. It is appropriately sized for a simple delete tool; the first sentence is a fragment, but that does not impede comprehension.

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 available there is no need to describe return values, and both parameters are schema-documented. The description covers the trigger, the destructive nature, and the approval requirement, which is enough for an agent to call the tool correctly, though it could say more about irreversibility or what the deletion affects.

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%, so both subscription_id and approval_id are already documented in the schema (approval_id even explains its single-use semantics). The description adds nothing about parameter formats or meaning, 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?

The description conveys a specific action on a specific resource ('stop a real-time notification subscription'), mapping cleanly to the tool name webhooks.delete. It does not name siblings (webhooks.create/list), but those are obviously distinct operations, so differentiation is inferred rather than stated.

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?

Gives an explicit trigger condition ('When the user wants to stop a real-time notification subscription'), which tells the agent when to reach for this tool. No exclusions or named alternatives are provided, but no competing delete/stop tool exists among the siblings, so the context is sufficient.

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