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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint, so the safety profile is covered. The description adds genuine context by enumerating the returned fields and the underlying GET route, though it doesn't discuss account scoping or auth beyond what the schema states.

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?

Three tight sentences, front-loaded with the verb and returned fields, then usage, then the alternative, then the route. The trailing 'GET /music/{song_id}' is slightly redundant but harmless.

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, the description usefully enumerates the response fields, so an agent knows what a read returns. Combined with annotations covering the safety profile and a fully documented parameter, the definition is complete for a single-ID read.

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 single song_id parameter is fully documented in the schema (including its format and that it runs on that song's account). The description adds no parameter detail beyond the schema, so the baseline of 3 applies.

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?

States a specific verb and resource ('Read one song') and enumerates exactly what is returned (title, duration, model, lyrics, style prompt, instrumental flag, mp3 link). It explicitly distinguishes itself from the sibling mureka_list_songs, which lists every song on an account.

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?

Provides clear when-to-use context ('before an edit, extend or remix to see what the song sings') and names the contrasting alternative mureka_list_songs for bulk listing. It stops short of a fully explicit when-not statement, but the routing is unambiguous.

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