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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds the non-obvious auth detail "(no API key needed)", which is genuinely useful behavioral context not present in structured fields; return format/pagination remain unstated, which is minor for a static example list.

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 tight sentences, front-loaded with the identity of the resource and followed by the usage scenario. No filler or redundancy.

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 no-arg, read-only list tool with annotations covering safety, the description plus annotations give an agent enough to call it correctly. The absence of an output schema is fine since results are examples, though it doesn't hint at the shape or count of returned items.

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?

The tool takes zero parameters, so there are no argument semantics to convey; the baseline for 0-param tools is 4. The description correctly implies no inputs are required.

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 (list) and resource (real Songbrain analyses of Songbrain's own songs), and clarifies the ownership scope so it's not confused with analyses of user songs. It does not explicitly differentiate from the sibling get_example_analysis, so an agent must infer the list-vs-single distinction from the name.

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?

"Use one to show what the API returns before analysing a user's song" gives a concrete when-to-use context (onboarding/demo). It doesn't name exclusions or explicitly compare against get_example_analysis, but the intended scenario is clear.

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