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

Beyond the annotations, the description discloses the login requirement (需要登录), that the other party is not notified (不通知对方), the 404 error semantics with a do-not-retry instruction, and the scope limitation that future icebreaking is unaffected. This is rich behavioral context well past the idempotent/destructive hints already in 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?

A dense but organized single block using 【】markers: login/action first, then behavior/error notes, then the chain and alternative. Every clause earns its place, though the run-on density is slightly harder to scan than a clean sentence split.

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 boolean setter with no output schema, the description covers auth, idempotency, notification behavior, error handling, scope, and alternatives. Nothing an agent needs to invoke it correctly is missing.

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% (muted true/false meaning, conversationId), so the schema already carries the parameter documentation. The description adds only a hint that conversationId comes from list_my_conversations (id/activityId), which is marginal sourcing help, so the 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 (静音/mute) and resource (本人DM/群 - the user's own DMs/groups), and explicitly contrasts the scope with the sibling set_notification_prefs for global push. An agent can distinguish this from conversation-list or notification tools 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?

Gives explicit when-to-use via the chain (list_my_conversations → get id/activityId → set), an explicit alternative (全局推送用set_notification_prefs), a scope exclusion (仅此会话，不改未来破冰), and a when-not-to-act rule (404 = no access or already left, 勿重试). Nothing is left to inference.

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