Complete tasks

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

The annotations already declare idempotentHint=true and destructiveHint=false, and the description's 'Safe to repeat' simply reiterates this. No new behavioral context is added beyond what annotations provide, such as return behavior or side effects. With annotations covering the safety profile, this is acceptable but not exemplary.

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 three sentences, each earning its place: the first states the action, the second provides usage guidance, and the third reassures idempotency. It is front-loaded and concise with no filler.

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 write tool with two parameters and no output schema, the description covers the purpose, the preferred usage over a sibling, and the safety of repetition. Combined with the annotations (idempotent, non-destructive), the agent has sufficient context to select and invoke the tool correctly.

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 input schema has 100% coverage with descriptions for both 'list_id' and 'task_ids'. The description adds no extra parameter-specific details beyond the schema. Since the schema already documents the parameters, a baseline score 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 uses the specific verb 'Mark' with the resource 'tasks done', clearly stating the tool's function. It also distinguishes from the sibling 'update_task' by explicitly saying 'prefer it over update_task for finishing things', making the purpose 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 explicit guidance on when to use the tool: 'This is the most common write by a wide margin — prefer it over update_task for finishing things.' It also notes 'Safe to repeat', reinforcing the idempotency for safe re-invocation. This gives clear direction on choosing this tool over alternatives.

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