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

With no annotations supplied, the description carries the full burden and does so: it discloses that changing title/detail/assignee rewrites unfinished occurrences while completed history is preserved, and that active=false only pauses future generation rather than deleting anything. It also states the login requirement and the assignee-eligibility constraint, which are exactly the preconditions an agent needs.

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?

Purpose is front-loaded and every clause carries information — preconditions, side effects, and the sibling alternative — with no filler. The semicolon-separated telegraphic style is dense and slightly clipped, but it stays readable and short.

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 6-parameter mutation with no annotations and no output schema, the description covers preconditions, mutation scope, history preservation, and the alternative tool. The only real gap is that it does not say what the call returns or how to confirm the series state changed afterward, which is minor for an update operation.

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% (only endDate is documented in-schema), so the description must compensate; it explains the semantics of title/detail (rewrite of unfinished occurrences), assigneeId (must be a goal collaborator, also rewrites occurrences) and active (pause-only flag). seriesId is left implicit as the targeting identifier, and the 'at least one optional field' constraint is stated though not tied to each named parameter.

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 names a specific verb and resource, '改现有周期规则' (modify existing recurring-series rules), and contrasts it with stop_task_series, so it is distinct from create_task_series/stop_task_series/update_collaboration_task. An agent can identify the tool without opening the 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?

It gives concrete use conditions: at least one field must change, the new assignee must already be a goal collaborator, and the agent should verify through get_collaboration_goal first. It also gives an explicit anti-pattern: '不要停掉再建' — do not stop the series and rebuild it, because stop_task_series revokes unstarted occurrences.

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