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

Annotations already declare idempotentHint=true and destructiveHint=false, and the description reinforces idempotency ('identical retries return the same plan') while adding genuinely new context: the five-minute cap, uncast-speaker reporting, the visualWorld-for-quoting prerequisite, and that there is no Brix36 planning model or credit charge. That is meaningful behavioral disclosure beyond the structured hints.

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?

Three tight sentences with the core action front-loaded, followed by input format, constraints, and cost. No filler, though the Brix36/credit-charge clause is somewhat internal jargon that could be trimmed for an external agent.

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?

Given a nested visualWorld object and an output schema (so return values need no explanation), the description covers the expected script format, the duration cap, idempotency, the quoting prerequisite and the no-cost/no-planning-model behavior. Only the sibling routing decision is left unspecified.

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 the baseline is 3, but the description adds a conditional constraint the schema does not make explicit — visualWorld is optional in the schema yet 'required for quoting' — and ties the cast/speaker handling to the reported uncast speakers. Useful added meaning over the schema text.

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 ('Imports finished screenplay-style Film text') and specifies the expected input shape (SCENE headings, NAME: dialogue), which lets an agent distinguish it from the incremental studio_film_scenes_write / studio_film_add_line siblings. It stops short of explicitly naming those alternatives, so sibling differentiation is inferable rather than stated.

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 conditional context — visualWorld is required for quoting, Film is capped at five minutes, uncast speakers are reported — but never says when to choose this tool over studio_film_scenes_write or the film line-editing tools. Usage is implied by the 'finished script import' framing rather than spelled out with exclusions.

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