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

Annotations already cover safety (readOnly=false, destructive=false, idempotent=true), so the description only needs to add beyond them. It does: it discloses cost ('Spends AI credits') and the asynchronous job model requiring polling, neither of which is encoded in annotations or schema. Return format is not described, but an output schema exists.

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 short sentences, front-loaded with the action and immediately followed by the two facts an agent most needs (credit cost, polling requirement). No filler.

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 6-parameter generation tool with annotations and an output schema, the description supplies the two non-obvious facts: credit spend and the async polling workflow. It is essentially complete, though it could note whether the queued job must be polled before the asset is usable.

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%, so every parameter (loop, durationSeconds, promptInfluence, idempotencyKey, workspaceId) is already documented with constraints and defaults. The description adds no parameter-level meaning, which is acceptable but warrants only the baseline score.

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 ('Queue a sound effect into the BlitzReels media library') and adds the async outcome ('returns a job'), which clearly separates it from a fire-and-forget mutation. It does not explicitly differentiate from the close siblings generation_music_create or generation_voiceover_create, which is the only gap.

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?

The description names the follow-up tool explicitly ('poll with generation_jobs_get'), which is useful routing context. However, it gives no guidance on when to choose a sound effect over the sibling music/voiceover generators, nor any preconditions or exclusions.

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