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

Beyond the annotations, the description discloses important behavioral nuances: loss of registration-only materials and replay access after exit, the tool not removing the user from activity groups, and the non-error behavior of returning joined=false when the user was never signed up. It also notes login requirements and the irreversibility of the related leave_conversation action.

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 structured with clear sections for when to use, combination chains, and pitfalls. It is dense but every sentence provides actionable information, and the key use trigger is front-loaded.

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?

Given the tool's complexity and lack of an output schema, the description covers the important edge cases: material access loss, group membership behavior, non-signup behavior, and routing to related tools. An agent has enough context to invoke the tool correctly and warn the user appropriately.

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?

The single parameter activityRef is fully described in the schema with type, length constraints, and guidance to use the value returned by get_activity or get_signup_activity. The description itself adds no additional parameter semantics, so the schema carries the full burden and the baseline 3 is appropriate.

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 title and description clearly identify the action: leaving a free online activity. It distinguishes itself from related tools by explicitly noting what it does not do (e.g., it does not remove the user from the activity group, unlike leave_conversation) and by referencing the sibling join_activity_online for switching activities.

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 gives a concrete 'when to use' trigger with user wording ('这场我不去了/别再给我推了'), and provides explicit alternatives for related actions: set_conversation_muted for noisy groups and leave_conversation for fully leaving the conversation. This gives clear routing guidance.

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