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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds useful context about the return (each song comes with a direct MP3 link) and the nature of the results (pre-made library tracks, not custom), which goes beyond the 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?

The description is three sentences, front-loaded with the core purpose, followed by clear usage guidance and a clarifying contrast with a sibling tool. Every sentence earns its place, and no information is redundant.

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 read-only tool with three optional parameters, an output schema, and full annotation coverage, the description is complete. It covers purpose, usage, return format, and the key distinction from custom song generation, leaving nothing essential for an agent to call it correctly.

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%, so all three parameters are already well documented in the schema with descriptions and examples. The description provides matching examples (language, genre, mood, occasion) but adds no new semantic detail beyond what the schema already conveys.

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 states a specific verb (finds) and resource (ready-made AI songs from the SongUp AI library) and notes the return format (direct MP3 link). It clearly distinguishes this tool from start_custom_song, but does not differentiate from the other sibling find_audio_tool, leaving a small ambiguity.

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?

It gives explicit when-to-use guidance ('Use it when the user wants to hear AI songs or example songs…') and when-not guidance ('not made from the user's own words; for a song from their own idea use start_custom_song'). However, it omits any reference to the sibling find_audio_tool, so the alternative routing is incomplete.

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