Render one frame of the current project so you can SEE it

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

Annotations already declare readOnlyHint=true and openWorldHint=true. The description adds valuable context about cost (FREE vs. render_video credits), return format (PNG image), and the ability to sample different time points. This goes beyond the annotations without contradiction.

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 concise: four sentences that front-load the core action and include all essential information. Every sentence contributes practical guidance (output, reason, cost, parameter default) with no wasted words.

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?

The description covers purpose, usage frequency, cost, return format, and parameter behavior. Combined with rich annotations and a complete schema, it leaves no important gaps for an AI agent to make an informed invocation.

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%, so the description adds marginal value. It reiterates that 'time' is in seconds and defaults to 0, which is already in the schema. It doesn't introduce new parameter semantics, but it does reinforce the usage context for time.

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 clearly states a specific verb and resource: 'Render a single frame of the current project to a PNG and return it as an image'. It distinguishes itself from render_video by emphasizing single-frame output and explicitly mentions return format. This makes the tool's purpose unambiguous.

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?

Provides explicit when-to-use guidance: 'This is how you check your work', 'Use it liberally', and specifies the appropriate moments (after composing/edits, at different times to inspect motion). It also contrasts with render_video by noting stills are free, clarifying when not to use the sibling tool.

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