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

Beyond the readOnlyHint annotation it discloses the exact fields to read (metadata.status, audio_url), the meaning of each status, that failed rows carry metadata.error and had credits refunded, and that reads cost no credits. This is rich operational context an agent cannot get from the annotations alone.

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?

Purpose and the polling role are front-loaded, and every sentence carries distinct information (status semantics, downstream impact, no-credit behavior). The downstream tool chain detail is useful but makes it longer than strictly necessary.

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 steps in to name the return fields and their states, and annotations cover the safety profile. An agent has everything needed to call and interpret the result correctly.

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 coverage is 100%, so all four parameters are already documented in the schema, including the fetch-vs-shown limit nuance and the audio_type guidance. The description focuses on output fields rather than adding parameter meaning, so the baseline 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 (List) and resource (a project's generated audio rows) plus ordering (newest first). It further distinguishes itself by declaring it is 'the POLL for lab_generate_music,' so an agent can identify its role among the many lab_list_* siblings without opening any schema.

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?

Explicitly frames the tool as the polling step for lab_generate_music and explains the consequences of pending/failed rows, which tells the agent when to call it. It does not spell out a when-not or a competing alternative list tool, so it stops short of the top tier.

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