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

Annotations include destructiveHint=true and idempotentHint=true. The description adds context beyond annotations by clarifying that it does not affect running machines, and it explains idempotency in terms of using a separate key for the cancel intent and retaining it on retry. However, it does not elaborate on what happens to the underlying resource or whether there are any side effects, which is partially covered by annotations. No contradiction found.

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 description is concise, three sentences, with no filler. It front-loads the primary action and scope, then provides retry guidance. Every sentence adds value, and it is well-targeted for an agent.

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 2-parameter tool, the description is complete. It covers purpose, alternative scoping, idempotency, and parameter source. The absence of an output schema is acceptable since the tool is a cancel action. The only minor gap is it doesn't describe the response format, but that may not be necessary given the simplicity.

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 covers 50% of parameters with description, specifically the idempotency_key has a detailed description. The 'id' parameter only has a type and length constraints. The tool description says to get the id from get_trial, which adds context for the 'id' parameter. This compensates partially for the low coverage, but additional detail on the 'id' parameter would be useful.

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 clearly states the action ('cancel a pending request') and the resource ('trial request'). It explicitly distinguishes itself from a sibling by noting 'does not delete a running machine,' and references the sibling tool (get_trial) for obtaining the ID. This is specific and 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?

The description provides clear context for when to use this tool: when the user wants to cancel a pending trial request. It also mentions using get_trial to obtain the ID, which implies a workflow. However, it does not explicitly state when NOT to use this tool (e.g., for deleting running machines) with alternative wording, though the current phrasing covers the exclusion indirectly.

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