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

Annotations already declare readOnly, idempotent, and non-destructive, so safety is covered. The description adds real behavioral payload context beyond that: it tells the agent the tool surfaces in-progress work ('uploads and analysis still running') and downstream stages (mix/master), which is exactly what an agent needs to interpret the result given no output schema.

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?

A single sentence enumerating the returned facets in a logical order (stems → in-flight jobs → confirmation → mix/master). No wasted words, though it is a verbless fragment that leans on the tool name for its action.

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 carries the return-shape burden and does so by listing the status fields an agent will receive. Combined with annotations covering safety, an agent has enough to call this correctly; only sibling disambiguation is missing.

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 songId's schema description already tells the agent to source the id from list_songs or create_song. The description adds nothing about the parameter, but with a single fully documented param this is the expected 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 names a specific resource (one song) and enumerates the exact status facets returned: stems/labels, in-flight uploads and analysis, label confirmation, and mix/master progress. It implies single-song scope versus a list, but never explicitly distinguishes itself from close siblings like get_song_session or check_mix.

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?

There is no explicit when-to-use, no prerequisites, and no mention of alternatives, despite get_song_session, check_mix, and get_analyzer_session all appearing to be adjacent status-checking tools. Usage is only inferable from the description of what data comes back.

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