Render a photo

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

Annotations already declare readOnlyHint=true, and the description adds useful behavioral context: path tracing, sun position from compass/time, lamps/glass, quality draft taking ~10s, and PNG output. No contradiction with annotations.

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 dense and front-loaded, with each clause contributing useful information. Minor cryptic phrasing like 'w/h small' and the telegraphic parameter list keep it from a perfect score.

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 an 8-parameter tool with full schema coverage and an output schema, the description covers core behavior, parameter relationships, and output format. It does not address sibling routing, but that is already handled under usage guidelines.

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%, but the description adds meaning beyond the schema by clarifying cam vs view/yaw/pitch relationships, hour as local solar time with examples, quality time estimates, and small w/h. This goes beyond simple parameter listing.

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 opens with 'Realistic photo' and specifies path tracing with sun, lamps, and glass, plus PNG output. This clearly identifies a photorealistic rendering tool and distinguishes it from siblings like render_plan and render_3d.

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 use for realistic photo rendering through 'Realistic photo' and view options, but it never explicitly states when to prefer this tool over render_plan or render_3d, nor gives exclusion criteria. The context is inferable but not stated.

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