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

Annotations already declare destructiveHint=true, idempotentHint=false and readOnlyHint=false. The description adds value beyond that: it discloses the 'can email subscribers' side effect and the notify_subscribers default, which the annotations cannot express. It still omits whether the cancellation is reversible.

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?

Four short, front-loaded sentences with the action first and the guardrail last. 'This can email subscribers' partially restates the preceding default sentence, a minor redundancy.

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 destructive, non-idempotent tool with no output schema, it covers the side effect, the parameter default, and the invocation guardrail. What remains missing, such as reversibility of a cancelled window, is secondary.

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 0%, so the description must compensate. It documents notify_subscribers' default (false) and its effect (emails subscribers), but window_id is left with no meaning beyond its name. Partial compensation merits a 3.

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 and resource ('Cancel a maintenance window'), which clearly separates it from create_maintenance_window and update_maintenance_window siblings. It does not explicitly name the alternatives, but the operation 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?

Adds an explicit precondition: 'Run only when the user asked to cancel this window in this conversation.' This is a real usage constraint that prevents speculative invocation. It stops short of naming alternatives, so it lands below a 5.

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