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

Annotations already declare the safety profile (not read-only, not destructive, not idempotent, closed world). The description adds real behavioral context beyond that: new shots inherit the ratio while existing shots keep their original, and it says what the return contains. It does not discuss auth/permission needs, but for this tool that gap is minor.

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-loads the core action and enumerates values first, then dependencies and return values in a logical flow. Slightly long with the enum values restated, but every clause contributes useful instruction.

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?

Even without an output schema, the description explains the return (aspectRatio and previousAspectRatio, null when unset) and covers the workflow dependency and inheritance behavior. Nothing an agent needs to invoke it correctly is missing.

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 the enum documents all five valid values, so the schema already carries the parameter meaning. The description repeats the enum values but adds little syntax or format detail beyond what is already in the schema, so baseline 3 is appropriate.

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+resource ('Set the project's frame shape') and enumerates the exact allowed values. It distinguishes itself from siblings by naming create_shots and get_project_outline, so an agent can tell what this does and where it sits 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 when it is needed ('before storyboard work: create_shots refuses while get_project_outline shows aspectRatio null') and gives a clear directive on user interaction ('Ask the user which ratio they want; do not pick one for them'). The condition that selects this tool is fully spelled out.

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