netease_play_mode

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

Annotations only declare that this is a non-destructive, open-world mutation; the description goes well beyond that by stating the operation preserves the current song, playback progress and paused state, that the shuffle queue plays each track exactly once, and that repeat_one does not block manual track changes. These are real behavioral traits an agent would not otherwise know. It stops short of covering failure behavior or return values.

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 single compact sentence with semicolon-separated clauses; the core action is front-loaded and every clause (state preservation, shuffle-once, repeat_one not blocking manual skip) carries distinct information. No filler.

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?

With no output schema and thin annotations, the description does the necessary work on side effects and mode semantics, which is what an agent needs to call this safely. The main residual gap is the unexplained requestId parameter and no mention of what the call returns or how errors surface.

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 0%, so the description must compensate. It does explain the semantics of the mode enum values (shuffle = each song once, repeat_one = manual switching still allowed), which is genuinely useful beyond the bare enum list. However, the required requestId parameter is never explained — no indication whether it is an idempotency key, correlation ID, or retry token.

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 names a specific verb (切换/switch) and resource (play mode) and enumerates all three enum values — sequence, shuffle, repeat_one — so an agent knows exactly what is being changed. It does not name a sibling tool by contrast, but the 'preserves current song/progress/pause state' clause implicitly separates it from netease_play/netease_pause/netease_next.

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?

Usage is implied rather than stated: an agent can infer this is the tool for changing playback mode, and the mention of manual track switching hints at interaction with netease_next/netease_previous. There is no explicit when-to-use/when-not statement or named alternative.

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