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

Annotations only declare it is a non-read-only, non-destructive, closed-world operation; the description goes well beyond that by explaining that new projects are created per language, that translations are constrained to roughly the same length so timing holds, that voiceovers are re-spoken by the same voice, and that on-camera speech is left untouched. Those are exactly the behavioral facts an agent needs before mutating a project, and nothing contradicts destructiveHint=false.

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?

It is a single dense paragraph that front-loads the output (variant projects with translated copy) before the workflow steps, and most clauses carry information. It runs slightly long and the naming-convention detail plus the tool cross-references could be tightened, but there is little 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 three-parameter mutation tool with no output schema, the description covers what gets created, how translations behave, which media is and isn't re-voiced, and the surrounding workflow. Gaps remain: it never says what identifiers are returned or whether the original project is altered, which matters since the tool is a write operation.

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 100%, so the baseline is 3, but the description adds real meaning: it explains that the voiceover re-speaking behavior is conditional on voiceovers made with add_voiceover and tied to the same voice, which corresponds to the voice flag. The languages semantics (one project per language, translation into that language) are also made concrete, though projectId and what happens to the source project are left unmentioned.

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 states concretely what is produced: a variant project per language named "<name> · DE", containing translated captions, titles and graphics copy, plus re-spoken voiceovers. That is a specific resource and effect, not a restatement of the name. It does not, however, distinguish itself from the adjacent create_variants or create_take_variants siblings, which an agent could easily confuse it with.

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 explicit sequencing guidance: run it on the finished, approved cut, verify each variant with render_frame, then export with export_projects. That is useful when-to-use context and names the follow-up tools. It still omits when NOT to use it — e.g. how it differs from create_variants — so the routing decision against siblings is left to inference.

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