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

With annotations only telling us this is a non-destructive, non-idempotent write, the description carries the real burden and delivers: it explains that recurring tasks are NOT closed but rolled to the next RRULE occurrence with taskStatus kept at 'needs-action', lists exactly which RRULE shapes can be rolled, and discloses the fallback (close as completed). It even names the response field (`rolled`) that reveals which path was taken. This is well beyond what the annotations provide.

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 primary action is front-loaded in one short sentence, followed by a dense but relevant second sentence covering the recurring-task exception, the RRULE restriction, the fallback, and how to detect which occurred. No sentence is padding.

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?

There is no output schema, and the description compensates by naming the `rolled` response field and explaining its meaning, which is exactly the information an agent needs to interpret the result. For a one-parameter mutation tool, the description is complete.

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?

There is a single parameter, taskId, and schema coverage is 100%, so the schema already documents that it accepts a full UUID or 8-char prefix. The description adds no syntax or format detail for the parameter itself, which is the expected baseline when the schema does the heavy lifting.

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+resource ("Mark a task complete") and immediately qualifies the semantics for recurring tasks, so the agent knows exactly what operation this is. It does not name or differentiate against close siblings like muninn_task_update or muninn_task_snooze, which could also touch task status, so it stops short of a 5.

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 effectively describes conditional behavior (simple RRULEs roll forward, complex ones close), which doubles as guidance about outcomes, but it never states when to prefer this tool over muninn_task_update or muninn_task_delete. Usage is implied by the outcome descriptions rather than explicitly contrasted with alternatives.

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