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

Annotations declare destructiveHint=true/idempotentHint=true, but the description adds substantial context beyond them: login required, free events lose visible materials/replays while paid events' login materials are unaffected, messages still arrive in the activity group, and unregistered users get joined=false.

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?

Dense but front-loaded: login requirement and consequences lead, then alternatives, then return value. It is information-packed and earns most of its length, though the run-on style slightly reduces readability.

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?

Covers the destructive consequences, auth requirement, the alternative operations, and the return value (joined=false) despite having no output schema. An agent has everything needed to call and reason about this tool 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 100% and the schema already documents activityRef as slug or id. The description mentions conversationId lookup via list_my_conversations, but that pertains to a different tool, so it adds little meaning about the actual activityRef parameter. Baseline 3 applies.

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+resource: leaving online participation in an activity (退出线上参会). It clearly distinguishes the action from related siblings like set_conversation_muted and leave_conversation, which it names as different operations.

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?

Explicitly routes to alternatives: use set_conversation_muted to mute, leave_conversation to fully exit the group, list_activities to switch events. It also gives the pre-condition to confirm before leaving (free vs paid consequences).

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