Complete one task

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

Annotations already indicate the tool is a non-destructive, idempotent write operation. The description adds that the marking is 'exactly' scoped to the supplied task ID, clarifying that no other tasks are affected, which is a behavioral trait not explicitly in the annotations. It does not describe edge cases like already-completed tasks, but the idempotent annotation covers that.

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 a single concise sentence with the action placed first and no redundant wording. Every word contributes to clarity, and it is appropriately sized for a function with one parameter.

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 mutation tool with one parameter and no output schema, the description covers the essential purpose and input. It could benefit from noting whether the task must be in a particular state or how this interacts with ongoing timers, but the idempotent and non-destructive annotations fill some gaps.

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?

With 0% schema description coverage, the description compensates by explicitly mentioning 'supplied task ID', indicating the parameter's role in identifying the task to complete. This adds meaning beyond the schema's bare property name, though it does not provide further constraints or examples.

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 'task' and state 'completed', making the action unambiguous. It also specifies 'exactly the supplied task ID', which distinguishes it from sibling tools like start_task or stop_timer that affect task state differently.

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 clearly implies the tool is for marking a specific task as completed, but it does not provide explicit guidance on when to use it versus alternatives such as stop_timer or plan_task_today. No exclusions or alternative references are given, leaving the comparison to inference.

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