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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so safety is covered. The description adds real behavior the annotations cannot convey: the URL is temporary and expires after six hours, and requests past the retention window return 410. It stops short of saying whether repeat calls mint a fresh URL or return the same one, which matters for an idempotent-flagged tool returning a time-limited artifact.

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?

Three short sentences, zero filler, with the core purpose front-loaded and the expiry and error behavior following in the order an agent would need them. Nothing repeats the annotations or the schema.

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 single-parameter read tool with no output schema, the description covers what it returns (a temporary MP3 URL), how long that result is valid (six hours), and the failure mode (410 past retention). Combined with annotations that already cover the safety profile, an agent has everything needed to call it and interpret the result.

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?

There is a single required 'id' parameter whose schema description coverage is 100%, so the schema already documents it, including the UUID pattern. The description adds no further meaning about the id (format, source, whether it is an episode id or a job id), which is acceptable at this coverage level and yields the baseline 3.

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 uses a specific verb and resource ('Get a temporary MP3 URL for a ready daily episode') and names the concrete return artifact, which separates it from a metadata tool like get_episode. It does not explicitly contrast itself with get_script_audio_download or get_script_audio_job, so an agent must infer that distinction from the word 'episode'.

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?

Preconditions are implied rather than stated outright: the episode must be 'ready' and inside the retention window, and the 410 note hints at when the call will fail. There is no explicit when-to-use guidance versus the script-audio siblings, and no statement of what to do if the episode is not yet ready.

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