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

No annotations are present, so the description carries the burden. It does disclose one behavioral detail: Google stamps the completion time itself, which tells the agent not to supply a time. However, it does not mention idempotency, effects on already-completed tasks, error handling, or return behavior. With no annotations, this is only partial disclosure.

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, front-loaded with the primary action. The second sentence is an informative behavioral note with no filler. Extremely efficient.

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 3-parameter mutation tool with no annotations and no output schema, the description is too sparse. It lacks instructions on how to retrieve valid listId/taskId values, what happens if the task is already completed, or what the response contains. The timestamp note adds value, but the absence of parameter sourcing guidance and flow details leaves an agent under-informed.

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. listId and taskId have no description in either the schema or the description. The names suggest their content but the description provides no guidance on where to obtain them (e.g., list_google_tasks, get_google_task). The tool name does add 'Google' context but not enough to compensate for the coverage gap.

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 specific action ('Mark a task done') on a specific resource (Google task). The second sentence clarifies a key behavior (Google sets the completion time). Distinguishable from siblings like complete_outlook_task by the 'Google' qualifier in the name and 'task done'. Clear and unambiguous.

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 implies the use case (complete a Google task) but provides no explicit when-to-use guidance or exclusions. It does not contrast with update_google_task, delete_google_task, or the Outlook counterpart. The behavioral hint about timestamp is a small usage cue, but not enough to rise above implied usage.

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