Find and play a YouTube song

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

No annotations are provided, so the description bears full responsibility for behavioral disclosure. It mentions returning a 'playback-ready URL' but does not detail any side effects, authorization requirements, rate limits, or behavior when no match is found. This leaves critical gaps for an AI agent.

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 extremely concise with two sentences: the first states the core functionality, and the second adds context for usage. Every word earns its place, and the structure is front-loaded with the most critical information.

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?

Given no output schema, low parameter coverage (0%), and no annotations, the description is minimally adequate. It conveys the primary output (one URL) and usage hint, but lacks details on error handling, best-match criteria, or authentication. It suffices for a simple tool but could be more comprehensive.

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%, meaning no parameter descriptions exist in the schema. The tool description does not elaborate on any parameter (e.g., query, regionCode, officialOnly, relevanceLanguage), failing to add meaning beyond the raw schema types and constraints. The parameters are mostly self-explanatory, but the description should have provided at least basic context.

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 finds the best matching song and returns a playback-ready YouTube URL. It distinguishes itself from the sibling 'youtube_search_song' by implying a single best result, and from 'youtube_get_video' by focusing on playback readiness. The mention of voice commands adds context.

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 recommends this tool for direct voice commands like 'play...', providing clear when-to-use guidance. It implicitly suggests alternatives such as 'youtube_search_song' for broader searches, but does not explicitly state when not to use it.

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