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

With no annotations provided, the description carries the full burden, and it delivers: it discloses the no-key/free nature, scale, return payload, the requirement to send openings in the same call, the checker behavior when openings are omitted, dimension ranges, and the coordinate system. This goes well beyond a minimal mutation description and gives the agent accurate expectations of side effects and outputs.

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 compact and dense, front-loading the most important facts (free, no key, creates plan, returns IDs), then covering alternatives, the openings requirement, constraints, and coordinates. Every sentence carries actionable information with no filler.

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 create tool with no output schema and no annotations, the description covers the essential context an agent needs: what it returns, how to choose between shape representations, mandatory openings behavior, numeric bounds, and coordinate orientation. Nothing critical is missing for a correct first call.

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?

Although schema coverage is 100%, the description adds crucial cross-parameter meaning not available in the schema: the mutual exclusivity of width_m/depth_m versus rectangles, the requirement to include openings, and the coordinate origin convention ('x to the right, y down, origin at the room's top-left corner'). This transforms bare parameter definitions into callable instructions.

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 names a specific action and resource: 'Creates a new plan at scale 1:50' and states what it returns ('project id plus purchase_url'). This clearly distinguishes it from sibling tools like check_plan, move_furniture, and show_plan, which perform different actions on existing plans. The purpose is immediately obvious.

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 operational guidance: use either width_m/depth_m or rectangles, 'never both', and always send openings in the same call. It also explains the consequence of omitting openings. It does not explicitly name sibling alternatives or state when not to use this tool, but the guidance for correct invocation is strong and excludes ambiguity.

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