Render the floor plan

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

Annotations already mark the tool read-only, so additional safety disclosure is less critical. The description adds meaningful behavioral details beyond annotations: the region is never cropped and grows on the short side, the background image is overlaid for comparison, and large w/h values increase token cost.

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 a single dense paragraph with the core purpose front-loaded. Every phrase earns its place, covering output format, framing behavior, background overlay, and token efficiency without fluff or redundancy.

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?

Given the rich input schema (100% parameter coverage), the output schema, and the readOnlyHint annotation, the description is nearly complete. It covers the most important behavioral constraints and rendering modes; minor details like the default grid setting and fully automatic region fitting are already present in the schema, so their absence here is acceptable.

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 baseline is 3. The description adds value by explaining the relationship between room and region, the pad default in centimeters, the purpose of bg for comparing with the reference, and the token-cost implication of large w/h values. Some duplication with the schema exists, but the added guidance is genuinely useful.

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 'PNG of the floor plan, exactly as the user sees it,' which names a specific output format and scope. It clearly distinguishes this from 3D/photo renderers and explains the two framing modes (region and room), leaving no ambiguity about what the tool produces.

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 gives clear context for use: it produces a PNG of the current floor plan, includes framing modes, background overlay for reference comparison, and token-saving guidance. It does not explicitly contrast this with sibling tools like show_plan or export_plan, but the usage context is strong enough for an agent to decide when to use it.

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