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

With no annotations, the description carries the behavioral burden. It discloses the weight formula (2.5 kg/m2 per mm of thickness), the optional waste and edge-work additions, cost outputs, and the web_url with a prefilled quote. It does not discuss edge cases or exact response formatting, but it is transparent about the tool's main computational behavior.

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 front-loaded sentence that leads with the tool's core purpose, then uses a colon-delimited list to enumerate calculations and outputs without filler. Every clause earns its place.

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 7-parameter calculator with no output schema or annotations, the description covers the essential invocation context: inputs, calculation formulas, optional additions, total/per-piece results, and the quoted web URL. It could add output field names or formatting details, but the description is sufficient for correct tool selection and invocation.

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%, so the baseline is 3. The description adds real semantic value beyond the schema by explaining how thickness_mm relates to weight and how waste_pct is applied on top of net area, which helps an agent understand the calculation model.

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 states a specific verb+resource: 'Cut-to-size glass cost and weight estimate.' It lists exact outputs and distinguishes this tool from sibling calculators by making glass the unmistakable subject.

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 when to use the tool: whenever a cut-to-size glass cost and weight estimate is needed. It does not explicitly name alternatives or exclusions, but the material-specific focus makes the appropriate use unmistakable among sibling calculators.

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