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

Annotations already declare mutation (readOnlyHint=false, non-idempotent), so the bar is lower, yet the description still adds real behavior: login is required, assigning non-self triggers a notification, dates are Beijing-time, and out-of-range monthday rolls to month-end. It does not describe failure modes or duplicate-submission behavior, keeping it from a 5.

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?

A single dense paragraph that front-loads the auth note and purpose before the conditional rules. No filler sentences, though the run-on style slightly reduces scannability of the individual constraints.

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-required/9-optional mutation with no output schema, the description covers the non-obvious parameters, the conditional requirements, and even explains the 'generated' return field (occurrence count). Remaining gaps (e.g. validation limits on title/detail) are minor.

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?

With only 22% schema coverage, the description must carry the load and largely does: it explains the freq-conditional weekday(1~7)/monthday semantics, the month-end overflow rule, the YYYY-MM-DD Beijing-time format, and assigneeId's collaborator/default-self rule. It leaves title/detail/goalId undocumented, but those are largely self-evident.

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 (建/create) and resource (目标周期任务 / goal recurring task rule), with the goal-level scope explicit. It further disambiguates by naming the modify (update_task_series) and terminate (stop_task_series) siblings, so an agent can place it precisely in the task-series family.

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?

Gives conditional invocation rules (WEEKLY requires weekday, MONTHLY requires monthday) and routes the agent to update_task_series for rule changes and stop_task_series for termination. Lacks guidance on when to prefer a series over a one-off task sibling, but the routing it does provide is concrete.

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