render_frames

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

Annotations already flag destructiveHint=true and readOnlyHint=false, so the mutation/side-effect profile is known. The description adds valuable behavioral detail beyond that: the call blocks until completion, can take minutes, and produces one written file per frame. It stops short of saying whether existing files are overwritten, but the destructive annotation lowers the burden.

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 two short bilingual sentences with no filler: it front-loads the purpose, then states return behavior and the blocking/performance warning. Every sentence adds information, and the warning is placed immediately after the core purpose.

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 a simple two-parameter tool with full schema coverage and a clear purpose, the description is nearly complete: it covers behavior, return value, output naming, and an important performance caveat. It lacks only an explicit pointer to sibling tools for other rendering workflows, and there is no output schema to elaborate the returned write results.

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 both 'path' and 'frames' are already documented in the input schema. The description adds some helpful context around output numbering and blocking, but it does not meaningfully explain parameter formats or constraints beyond what the schema provides. 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?

The description states a specific action ('Render an explicit list of frames'), the exact resource (frame numbers), and the output behavior (one file per frame, numbered by frame index). It also says it returns the write result for each file, which disambiguates it from nearby render tools like render_animation or render_still.

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?

The description implies when to use it: when the caller has an explicit list of frames rather than a full sequence. It also warns that a whole batch is slow and blocks, which is cautious guidance. However, it never names alternatives or states when not to use this tool, leaving sibling differentiation mostly implicit.

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