普通播放下一首

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

Annotations already show readOnlyHint=false and idempotentHint=false, so the agent knows this is a mutating, non-idempotent action. The description adds useful context: it is a 'direct' command to the 'current' player and does not control the screen, clarifying the mechanism and scope. It does not describe error behavior, but for this simple action the added context is meaningful.

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?

Two short sentences, both informative. The first states the action, the second defines applicability boundaries. No filler or repetition, front-loaded with the core action.

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 zero-parameter, no-output-schema action tool, the description covers the action, the target, and the critical exclusions (screen control and listen-together). It does not state prerequisites like the player being active, but given the simplicity and the sibling context, it is largely complete.

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 input schema has zero parameters, so there is nothing for the description to explain about parameters. Baseline for 0 params is 4, and the description appropriately focuses on the action and scope rather than parameter details.

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 uses a specific verb and object: '向当前网易云播放器发送下一首命令' (send next-track command to the current NetEase player). It explicitly distinguishes itself with '不操控屏幕，也不用于一起听房间', separating it from screen-control and listen-together sibling tools.

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 clearly states when to use it: '仅用于普通播放' (only for normal playback). It gives explicit when-not conditions by excluding screen control and listen-together rooms, but it does not name the alternative sibling tools that should be used in those cases.

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