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

Annotations already establish read-only, idempotent, non-destructive, closed-world behavior. The description adds useful operational detail beyond that: results come back in requested order, up to 20 per answer, and overflow seconds are returned in still_to_look_at for the next call.

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?

The description is front-loaded with what the tool returns, then adds the usage constraint and the free/non-mutating note. Every sentence contributes to selecting or correctly using the tool.

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?

There is no output schema, so the description carries the burden of explaining return behavior, and it does: pictures are returned in order, batched at 20, with remaining seconds surfaced in still_to_look_at. Together with the annotations and fully documented parameters, this is sufficient to call the tool correctly.

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 schema already explains seconds, render_id, and project_id. The description reinforces the seconds array as still-per-second moments but does not add meaningfully more about render_id selection or project_id than the schema provides.

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 a specific action and resource: seeing a finished Editor render at named seconds, returning one still per second. It is clear what the tool produces, but it does not explicitly distinguish itself from nearby siblings such as premiere_frame or get_editor_export.

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 a clear workflow instruction: inspect every moment renderChecks flagged before speaking about the render. It also notes the tool is free and changes nothing. However, it does not name alternatives or state when not to use this tool.

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