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

Annotations only declare the generic safe-mutation profile (readOnlyHint false, destructiveHint false); the description adds the operationally decisive facts: the call is non-mutating until apply_plan, it can incur a small charge from a planning model, and it may take minutes with an async result. Those are exactly the behavioral traits an agent cannot infer from the 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?

Front-loaded with purpose, then return shape, then consent/cost, then latency handling, then exclusions — each sentence carries a distinct decision-relevant fact. No filler or repetition despite covering a lot of ground.

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 still spells out the return payload (steps, per-step costs, choices, plan_id) and the not-ready case. Combined with the consent, cost, and latency notes, an agent has everything needed to call this correctly and handle its result.

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 50% because project_id has no description. The description compensates for the important parameter by defining `request` as the person's own words and enumerating sample change types, which tells the agent what level of natural-language input to pass. project_id is left implicit, keeping this below a 5.

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 ("Ask the Co-Director for a change to a built film") and immediately grounds it with concrete examples of what a change is (recast, rewrite a shot, redo a scene's look, trim the cut). It also names the sibling it hands off to (apply_plan), so an agent can place it precisely in the workflow.

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?

Explicitly says nothing changes until apply_plan, requires getting the go-ahead first because drafting may charge, and gives the fallback path (get_status(plan_id)) when the plan isn't ready. It also lists what this tool cannot do (score, dialogue audio, upscaling, retake cuts), which is real exclusion guidance rather than vague context.

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