render_preview

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

Implies read-only behavior (renders to view) but does not explicitly confirm non-destructive nature. No annotations to supplement, so description carries burden but is partially adequate.

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?

Two sentences, no fluff, front-loaded purpose. Every sentence adds value.

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?

Covers purpose and two parameters but misses explaining the required filename parameter and does not mention prerequisites or output format. Adequate for simple use but incomplete.

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?

Only frame (1-based) and scale (default 8x for small sprites) get description. Filename is required but unexplained; schema has 0% coverage, so missing critical parameter meaning.

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?

Clearly states it renders a single frame to PNG and returns viewable image. Use this to 'see' your work. Distinguishes from sibling export tools by focusing on preview rather than saving.

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 some guidance ('Use this to *see* your work') but does not explicitly differentiate from alternatives like export_png or state when not to use.

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