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

Annotations carry only the mutation/destructive profile (destructiveHint=true, readOnlyHint=false); the description adds genuinely new behavioral facts the schema cannot express: async execution, exact return shape ({job_id}), relative latency ('longest LLM step'), and a processing boundary (video deliberately deferred to animate_segment). The @real-media tag constraint also discloses a failure condition in advance. No statement contradicts the annotations.

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?

Four sentences, each carrying distinct information in a logical order: purpose → prerequisite → scope boundary → async/latency. Critical facts are front-loaded and there is zero redundancy or filler; the density is justified by the tool's async, multi-phase complexity.

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 an async tool with no output schema, the description covers what it does, what it requires, what it deliberately excludes, and what it returns — enough for correct invocation. The only omission is an explicit pointer to poll via await_jobs, though that is inferable from the {job_id} return and the sibling list.

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% and each parameter already carries a rich description referencing sibling tools (list_models, get_section_template). The tool description adds only indirect context — the voiceover prerequisite implies project_id must reference a voiced project, and 'director and art styles' explains what drives model/settings choice — but no parameter-specific meaning beyond the schema.

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 ('Plan') and resource ('the full visual storyboard') with enumerated deliverables — segments, shot pacing, image/video prompts, overlays, continuation chains. The visual-planning focus differentiates it from siblings like generate_script, generate_voiceover, and generate_segments, and the 'full' scope distinguishes it from per-segment tools.

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 an explicit prerequisite ('Requires voiceover to exist (timing comes from it)') that tells an agent when it is valid to call, and routes the next pipeline step to animate_segment ('generated video is added... with animate_segment'). Lacks an explicit when-not-to-use statement naming alternative planners such as generate_segments, so it falls short of a 5.

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