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

Annotations already declare destructiveHint=true, idempotentHint=false and readOnlyHint=false, so safety and mutation semantics are covered structurally. The description adds that completion time is stamped or cleared and that only the caller's own tasks are affected, but says nothing about failure modes (e.g. unknown activity_id) or permission requirements.

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 tight sentences, front-loaded with the primary action and immediately following with the inverse path and the required field. No filler.

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 tool with no output schema, the description covers the primary action, the revert path and the required input. Only minor gaps remain: no error behavior and no mention of what the caller does with the result.

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 coverage is 50%: done already documents its true/false semantics and the description merely restates it, while activity_id is undocumented in both places beyond 'required'. The description adds no format or lookup guidance for activity_id, so it does not 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 verb (mark done / reopen) against a specific resource (the caller's sales tasks/activities), and covers both directions of the operation. It is clearly distinguishable from list_sales_tasks and log_deal_activity.

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 explains the done=false reopen path, which is useful usage guidance, but never states when to reach for this tool versus siblings like list_sales_tasks or log_deal_activity, nor any prerequisites such as ownership of the task.

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