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

With no annotations, the description carries the full burden. It does disclose one behavioral consequence: completed tasks drop out of list_outlook_tasks by default. However, it does not mention reversibility, permission requirements, or other side effects of marking a task complete.

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?

Two short sentences with no filler. The action is front-loaded and the behavioral note is relevant. Every word earns its place.

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?

The description does not explain where to obtain listId and taskId (e.g., from list_outlook_tasks), does not mention the return value or errors, and lacks guidance on idempotency. For a mutation tool with no annotations and no output schema, this is a significant gap.

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 only 33% (only mailbox is described). The description does not compensate by explaining listId or taskId, leaving two required parameters without semantic guidance beyond their names.

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 states a specific verb and resource ('Mark a task as done'), making the primary purpose unambiguous. It implicitly distinguishes from complete_google_task by platform, but it does not explicitly contrast with update_outlook_task, which could also modify task status.

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?

No guidance is given on when to use this tool versus alternatives like update_outlook_task or delete_outlook_task. The only additional information is a consequence (tasks drop out of list_outlook_tasks), not a usage condition or exclusion.

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