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

Annotations already declare destructiveHint=true, idempotentHint=false, and openWorldHint=true, so the safety profile is largely covered. The description adds the subtask-gating requirement and summary content constraints, but never explains what the destructive part actually affects (e.g., whether subtasks are auto-closed, whether the action is reversible).

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?

Three short sentences, front-loaded with the action, then the summary constraint, then the conditional prerequisite. No filler or restatement of the tool name.

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?

With six parameters, four required, a fully documented schema, and annotations present, the definition covers the essentials for invocation. It is thin on outcome behavior though -- there is no output schema, and the description never says what the agent gets back or what happens to open subtasks under each policy.

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%, so every parameter is already documented, and the baseline is 3. The description adds only marginal meaning -- the instruction to omit test counts and file lists from the summary -- and never mentions filesTouched or the enum trade-off between complete-subtasks and override.

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 opens with a specific verb and resource: "Mark a task as done," which is clearly distinguishable from siblings like task_start, update_task, and delete_task. It stops short of explicitly naming a sibling it is not, so it does not reach the top of the scale.

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?

It states one real conditional rule -- incomplete subtasks require an explicit completionPolicy -- which tells the agent a prerequisite exists. However, it gives no guidance on when to choose this over update_task (e.g., partial progress) or task_start, so usage is only partially implied.

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