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

Annotations already declare idempotentHint=true, readOnlyHint=false, destructiveHint=false, and openWorldHint=true. The description adds meaningful behavioral context: it requires login, it is idempotent, it works for both groups and DMs, and it returns 404 if the user left the conversation or is not in it. It doesn't contradict annotations. The only minor gap is not detailing side effects on notifications, but the description covers the key behavioral traits beyond the annotations.

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: a one-line purpose, a comparison to the sibling tool, a practical selection guide, and an error condition. Every sentence earns its place and the most important information (what it does and how it differs) 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?

For a simple two-parameter mutation tool with full schema coverage and annotations covering idempotency and safety, the description is complete. It covers the key decision context (when to use vs. set_notification_prefs), how to find the right conversationId, and the 404 edge case. No output schema exists, but the tool's return value is not critical for correct invocation.

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%, so the schema already documents both parameters (conversationId and muted). The description adds context about how to obtain conversationId via list_my_conversations and clarifies the muted semantics ('true 设为免打扰 / false 取消'), but this largely mirrors the schema. Baseline 3 is appropriate since the schema does the heavy lifting.

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 sets or cancels do-not-disturb for a conversation, works for both groups and DMs, and is idempotent. It also distinguishes itself from set_notification_prefs by framing it as a milder, per-conversation alternative. This is a specific verb+resource with clear scope.

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 explicitly tells the agent when to use this tool versus set_notification_prefs, explaining the trade-off (milder per-conversation mute vs. disabling all DMs). It also provides a concrete selection strategy using list_my_conversations and get_conversation to identify active groups vs. icebreaker intro groups vs. DMs, and notes the 404 condition for left conversations. This is exemplary usage guidance.

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