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

Beyond the annotations (idempotentHint=true, destructiveHint=false), the description adds genuine behavioral context by stating it gracefully stops operation at next checkpoint, implying a non-immediate, non-destructive cancellation, and returns confirmation. These details align with the annotations rather than contradicting them.

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?

The five short sentences are aggressively front-loaded: purpose, required input, mechanism, return, and follow-up all appear in order with zero filler. Every clause earns its place.

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 simple async cancellation tool, the description covers the essential contract: what is required, how the stop behaves (at next checkpoint), what is returned (confirmation), and what to do next. With no output schema, the exact shape of the confirmation is still vague, and error cases (such as operation not found) are unaddressed, but nothing critical blocks correct invocation.

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?

The schema already documents operationId (The operation ID) and the feedback field in detail, giving roughly 67% coverage. The description restates that operationId is required but adds little semantic meaning, and _requestId remains unexplained.

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?

Cancel running operation states a specific verb (cancel) and resource (a running operation) in a single clear clause. The closing sentence explicitly routes the agent to checkOperationStatus, distinguishing this tool from its closest sibling without opening any schemas.

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 description names the required operationId as a precondition and gives a concrete working flow: cancel, then use checkOperationStatus to verify. However, it gives no explicit when-not-to-use guidance, such as avoiding cancelling already-completed operations.

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