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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), and the description adds genuinely non-obvious behavior: the stock-length selection rule (least total length, then least offcut, then fewest boards), the first-fit-decreasing algorithm with the honest 'feasible, not proven optimal' caveat, and unit-parsing tolerance. These are traits an agent could not recover from the schema.

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?

Purpose is front-loaded in the first clause and every sentence carries substance (outputs, optimization rule, algorithm caveat, units, return). The middle semicolon-chained sentence about tie-breaking is dense and slightly overloaded, but nothing is redundant.

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 35-parameter tool with an output schema and full schema descriptions, the description is largely self-sufficient: project types, optimization policy, algorithm quality, and the return artifact are all stated. The main gap is that it never clarifies which parameters apply to which project variant, leaving that cross-referencing to the schema.

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 description coverage is 100% across all 35 parameters, so the schema already documents every field including defaults and per-project applicability. The description's only parameter-level addition, 'Lengths accept feet and inches,' largely restates the schema's repeated unit examples, so baseline 3 is correct.

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?

Names a specific verb (plans) and resource (trim board order for board-and-batten, wainscoting, or picture-frame molding on one wall), and enumerates the concrete outputs (spacing, cut list, boards per retail length). An agent can distinguish this from the flooring/wallpaper planners and from build_order_sheet without opening the schema.

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?

Usage is implied by the scoping phrase 'on one wall' and the project enum, and the mention of a returned plan link hints that a separate order-sheet tool exists. But there is no explicit when-to-use/when-not guidance and no named alternative such as build_order_sheet, so the agent must infer the boundary.

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