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

Annotations already declare readOnlyHint, idempotent and non-destructive, so the description carries a lower burden. It still adds meaningful traits beyond the schema: the call is free with no credit charge or new generation, and the owner can read the exact transcript alongside the audio. It doesn't say how the audio is delivered (URL vs inline), which keeps it short of a 5.

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 action and the key cost fact, then the workflow context. Nothing is redundant.

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 low-complexity read-only tool with no output schema, the description covers the intent, cost, and outputs (audio plus transcript). However, it omits any param-level meaning and the audio return mechanism, which are the remaining gaps an agent needs.

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 0% for two required UUID params, so the description must compensate. It only hints that IDs come from soclo_hosted_voices_design_status and never distinguishes designRequestId from previewId or explains what each identifies, leaving an agent to guess which ID goes where.

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 (play) and resource (an existing private voice preview) plus the output modality (audio). The mention of soclo_hosted_voices_design_status as the transcript/ID source distinguishes it from the design, save, and quote siblings.

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?

Places the tool in a workflow: use it to listen and read the transcript before choosing a voice, with IDs coming from design_status. It lacks explicit when-not-to-use guidance or a named alternative for creating a new preview (soclo_hosted_voices_design).

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