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

With no annotations, the description must disclose behavior. It states inputs and outputs (sheets, screws, mud, tape), but does not explain rounding, unit assumptions, or confirm it's non-mutating. It is adequate but not rich.

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 entire description is one efficient sentence with a dash, front-loaded with purpose. Every phrase adds information, no fluff.

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 tool's simplicity (3 numeric inputs, no output schema), the description covers essentials: purpose, inputs, and expected outputs. It could mention units or calculation assumptions but is complete enough for basic use.

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?

The schema has no descriptions (0% coverage), so the description compensates by naming each parameter: "total wall and ceiling area" for wallArea, "waste percent" for wastePct, and "sheet size" for sheetAreaSqFt. It adds meaning beyond the parameter names, though it lacks explicit units or examples.

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 clearly states its function: "Calculate how many drywall sheets you need for a room" with a specific verb and resource. It also lists inputs and outputs, distinguishing it from other material calculators like tile_calculator or concrete_calculator.

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 sets clear context for use: when you need drywall sheets for a room, and what inputs to provide. However, it does not mention alternative tools or exclusions, so it doesn't earn a 5.

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