unmark_done

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

Annotations already declare readOnlyHint=false, destructiveHint=false, and idempotentHint=true, so the safety profile is covered. The description adds valuable behavioral context: it requires the Full Access Token, works on generated instances of recurring tasks, does not adjust kudos, and documents the verified 500-on-missing-document behavior. This goes beyond the annotations without 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 description is compact and front-loaded with the core action, then adds necessary caveats. Each sentence earns its place, though the error-code detail is slightly verbose for a tool description.

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 mutation tool with an output schema and annotations covering idempotency and destructiveness, the description is nearly complete. It covers auth requirements, edge cases (recurring tasks, kudos), and error behavior. The only minor gap is not describing the success response shape, but the output schema likely covers that.

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% and the only parameter, item_id, is already described as 'Task ID'. The description does not add further meaning to the parameter beyond what the schema provides, so the baseline of 3 is appropriate.

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 verb 'Undo' and the resource 'a task's completion', and specifies the exact effect (sets done=false and clears doneAt via /doc/update). It distinguishes itself from mark_done and unclaim_reward_points, so an agent can tell it apart from siblings without opening 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 explicitly notes when to use it (to undo a completion) and names the alternative for undoing reward points (unclaim_reward_points). It also warns about the 500 error case for non-existent documents, giving clear context for when the tool may fail.

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