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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds the useful detail that the tool returns the full attribute set (licenses availability, similar songs), which signals completeness. It does not discuss rate limits, auth needs, or behavior when a title matches multiple songs.

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 sentences: the first front-loads the purpose and enumerates return fields, the second cleanly documents the accepted identifier forms. No redundant or filler text.

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 single-parameter read tool with full schema coverage and annotations covering safety, the description is nearly complete. It omits only edge-case behavior (ambiguous title matching, error handling), which is minor given the tool's simplicity.

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 schema already documents the 'song' parameter with the same three accepted forms. The description repeats that information without adding syntax, format, or disambiguation rules (e.g., what happens with an ambiguous exact title). Baseline 3 is appropriate when the schema does the heavy lifting.

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 ('Full details for one Starchild song') and enumerates the exact fields returned (writers, genres, moods, key, tempo, production styles, similar songs, licenses). This distinguishes it from siblings like search_songs (discovery) or play_song (playback). An agent can tell exactly what this tool retrieves.

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 phrase 'for one Starchild song' alongside the accepted identifier forms ('song id, its starchild.music link, or its exact title') implies this is the lookup tool for a known song, versus search_songs for discovery. However, it never names search_songs or an exclusion condition, so usage is inferable but not explicit.

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