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

With readOnly/idempotent annotations already covering the safety profile, the description usefully adds a conditional behavior: extra web-wide numbers appear only when the artist has connected their own Songstats account. It also instructs how to report missing values ('not reported yet', never zero), which materially affects output interpretation.

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 opening sentence is a long run-on list of data categories that is hard to parse and partly redundant with later sentences. Usage triggers and the 'not reported yet' rule are valuable, but the enumeration is bloated for what an agent needs to select and invoke the tool.

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?

There is no output schema, so the description carries the burden of explaining returns and does so thoroughly, covering both track-level and catalog-level data plus the connected-account conditional. Complete enough to call correctly, with only minor ambiguity from the dense enumeration.

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 the artist/album_id/track_id semantics are already fully documented in the schema, including the label-connection requirement and the leave-out-both meaning. The description adds no parameter-level detail beyond the schema baseline.

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 establishes that this tool returns performance metrics (streams, saves, growth, sources, audience demographics, socials) per track or for the whole catalog. It is specific about the resource and scope, though it never explicitly names a sibling it is distinct from, relying on the agent to infer the boundary against get_track or promo_results.

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 concrete triggers: answer 'how is my release doing', write a pitch or bio from real numbers, or suggest where to focus next, plus handling guidance for missing figures. It lacks explicit when-not or named alternatives, but the context is clear.

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