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

Annotations already declare readOnlyHint=false and destructiveHint=false, and the description is consistent with a write operation. It adds real value beyond them by naming the exact state transition and the timestamp side effect ('le escribe completed_at'), plus a warning that update_task preserves the stale closing date. It stops short of describing the response or idempotency behavior.

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?

Front-loads the action and its side effect in the first sentence, then spends the remaining space entirely on disambiguation that prevents a wrong tool choice. No filler or repetition of the title.

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 two-parameter mutation with full schema coverage, annotations, and no output schema, nothing essential is missing: what changes, when to call it, and which sibling handles the inverse case are all present.

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%: task_id and workspace_id are both documented in the schema, including the fallback of using the workspace name. The description adds no parameter-level detail, so the baseline 3 applies.

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?

States a concrete verb+resource: marks the task as `completed` and writes `completed_at`. The effect is fully specified so an agent can distinguish it from update_task and rollback_task without opening any schema.

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?

Gives an explicit trigger condition ('cuando la persona confirma que la hizo, no cuando lo parece') and routes to alternatives: rollback_task for un-completing (which also clears the closing date) and update_task, whose drawback is explained. Both when-to-use and when-not-to-use are covered.

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