获取歌词

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the description's added value is in disclosing the return payload (原文、翻译、罗马音) and the conditional nature of the translation/romaji via '（如果有）'. It doesn't cover failure cases (e.g., missing lyrics, region-locked songs), which keeps it below a 5.

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 the resource and returned fields front-loaded. No filler or repetition of the title.

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 read tool with full schema coverage and readOnly annotations, the description compensates for the absent output schema by listing return fields. Only edge behavior (empty result, timestamp format interaction) is left unaddressed.

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 description adds nothing about the 'id' or 'with_timestamps' parameters. The default 3 baseline is appropriate when the schema alone carries parameter semantics.

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 ('获取') and resource ('歌曲歌词') and enumerates the returned content (原文、中文翻译、罗马音), so an agent can tell it apart from get_song_detail. It stops short of explicitly naming a sibling to differentiate itself from, so it falls just under a 5.

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 only implied: you call it with a song id when you need lyrics. There is no statement of when to prefer this over get_song_detail, no mention of prerequisites (login/region), and no exclusions.

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