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

Annotations declare a non-read-only, idempotent, non-destructive operation, and the description explains why: it persists a SoundCloud full-recording or preview timing basis, so it requires read and write access. It also reassures that the recording and queue are unchanged, which meaningfully bounds the mutation beyond what the annotations state. It does not cover behavior on missing/unauthorized items or the response shape, but the output schema covers returns.

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 tight sentences, front-loaded with the core action, then side effects, then the access requirement. Little waste, though the opening clause is denser in product jargon than necessary for a routing signal.

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 two-parameter, non-read-only tool with an output schema, the description covers the mutation's nature, its non-effects, and auth needs, which is a solid base. However, with zero schema description coverage, the parameters remain unexplained, and an agent gets no signal on failure modes or what 'current card' means in practice.

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%, so the description must carry the burden for sessionId and itemId, yet it never explains either. The phrase 'item already admitted to the current card' faintly implies itemId is card-scoped, but sessionId semantics (is it the card/session identifier?) are entirely absent.

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 verb+resource: it resolves playback for an item and refreshes expiring media URLs. It also scopes the operation to 'an item already admitted to the current card'. It stops short of differentiating itself from plausible siblings such as make_playable or get_story_audio, and the phrase 'application-only playback resolution' is somewhat opaque jargon an agent may not parse on first read.

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?

Use is implied by the precondition that the item must already be admitted to the current card, which tells the agent this is not the tool for admitting new items. There is no explicit statement of when to prefer this over siblings like make_playable, and no when-not guidance or failure conditions.

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