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

Beyond the annotations (readOnlyHint=false, idempotentHint=true, destructiveHint=false, openWorldHint=true), the description adds two meaningful traits: it consumes AI credits and it produces an asynchronous job rather than a finished asset. The credit-spend warning is valuable operational context an agent cannot infer from structured fields.

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 tight sentences with no waste. The core action ('queue a text-to-speech voiceover') is front-loaded, and the secondary facts (cost, async polling) follow in a logical order.

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?

An output schema exists, so return values need not be explained, and the description still covers the async nature and cost. The only minor gap is that it does not clarify workspace defaults or idempotency behavior, though the schema covers both.

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 (text, speed, voiceId, voiceStyle, workspaceId, idempotencyKey) is already documented, including the catalog lookup hint for voiceId. The description adds no syntax or format detail beyond the schema, which is the expected baseline when the schema does the heavy lifting.

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 text-to-speech voiceover') and names the destination ('BlitzReels media library'), which cleanly distinguishes it from siblings like generation_music_create and generation_sound_create. An agent can identify the operation without opening the 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?

It gives follow-up guidance by directing the agent to poll with generation_jobs_get, which is genuinely useful. However, it never states when to choose this tool over the other generation_*_create siblings, so usage selection is only implied by the resource name.

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