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

Annotations already indicate destructiveHint=true, but the description adds critical behavioral context: changing title/description/assignee rewrites all not-yet-done instances while completed ones are untouched, active=false pauses generation, and stop_task_series would break history. This exceeds what annotations alone convey and fully discloses side effects.

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 description is well-structured with clear sections (需要登录, 何时用, 组合链, 口径/坑), front-loaded with purpose, and includes only necessary warnings and context. No wasted words; every sentence 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?

For a destructive update tool with no output schema, the description covers all essential aspects: how to obtain seriesId, what can be modified, side effects on instances, collaborator requirement, minimum modification rule, and the alternative to avoid. An agent has everything needed to invoke it correctly.

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 17%, so the description must compensate. It explains assigneeId (must be a collaborator), title/detail (rewrite instances), active (pause), and endDate (set end date) in context. While it doesn't explicitly enumerate each parameter, it adds meaningful usage semantics beyond the schema.

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 clearly states the tool modifies an existing recurring task rule (改一条已有周期规则) and lists the specific editable fields: assignee, title/description, end date, and active flag. It distinguishes itself from stop_task_series by explicitly warning against using the stop-and-recreate approach, making the purpose 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?

Provides explicit 'when to use' guidance, a composition chain (get_collaboration_goal → this tool → verify), and clear exclusions (do not use stop_task_series, with reasoning). It also states conditions like new assignee must be a collaborator and at least one modification is required.

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