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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed world), and the description adds genuinely new behavioral facts: the link is short-lived (≤5 min) and remains valid only while result access holds, the key is unrevoked, and the question recording has not been replaced. It also states the permission model mirrors get_quiz_answers. It stops short of describing the response payload (URL field, expiry timestamp).

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?

Four tight sentences, front-loaded with the verb, TTL, and purpose, followed by the sibling differentiation and invalidation conditions. No filler, though the permission clause is tersely compressed into a single reference rather than spelled out.

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?

Given four required parameters, no output schema, and a read-only annotation profile, the description covers lifetime, invalidation, permissions, and the sibling gap well enough to call the tool correctly. Only the returned structure and error behavior on an expired link remain implicit.

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 the purpose enum is already documented in the schema (playback = compatible copy, download = original file), so the description adds no parameter-level meaning beyond it. It only hints at the identifier chain via the get_quiz_answers reference. Baseline 3 applies when the schema carries parameter semantics.

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 and resource (issues a short-lived link to an audio/video answer recording) plus its lifetime (up to 5 minutes) and its two intended uses (listen or download). It also explicitly separates itself from get_quiz_answers, which returns only the asset data and transcript, so the agent can distinguish the two without opening either 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?

Routing guidance is explicit: when you need the actual recording rather than answer metadata, get_quiz_answers will not serve it and this tool is the alternative. What's missing is an explicit inverse condition (no guidance on when NOT to call it, e.g. for metadata-only needs) or on handling an expired link.

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