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

Goes well beyond the annotations by disclosing that the operation SPENDS CREDITS (≈25 per b-roll clip plus a flat premium when starterBundle=true), that the exact amount returns as creditsReserved, that it is refunded automatically on failure, and that builds take several minutes. Annotations only flag destructive/openWorld; the cost, refund, and latency behavior is the real added value.

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?

Front-loads the core purpose and the credit warning, and every sentence carries information (async, cost, polling, duration, starter bundle). The caps emphasis and stacked clauses make it slightly dense, but there is 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?

With no output schema, the description carries the return contract adequately: it returns a build job immediately with an id to poll. Cost, refund, latency, and the polling channel are all covered, so an agent has everything needed to invoke and follow up correctly.

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 coverage is 82%, so the schema already documents most parameters. The description still adds meaning beyond it by explaining starterBundle's first-build pricing semantics and reinforcing the per-clip credit cost of brollCount, though turbo, resolution, and prompt get no extra description-level context.

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 (kick off an async build) and resource (influencer's vault), and enumerates exactly what the vault contains (character/reference sheet, on-camera stills, faceless b-roll, short clips). It also names the sibling polling tool get_influencer_vault_build, letting an agent distinguish it from generate_influencer_look or generate_influencer_studio_image without opening schemas.

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?

Gives explicit conditions: poll get_influencer_vault_build until status 'completed', and pass starterBundle=true for the very first build after create_influencer. It warns not to poll as if instant. It does not, however, contrast usage against adjacent generation siblings (generate_influencer_look, generate_influencer_snack), so exclusions are only partial.

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