engineering.hazen_williams_flow

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

Annotations already establish this as a read-only, idempotent, closed-world calculation. The description adds useful behavioral detail beyond that: the empirical water-only restriction, the zero-head-loss edge case, and 30-significant-digit exponent handling. It does not discuss invalid inputs such as negative length or diameter.

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 front-loaded with the formula and then explains variables, applicability, and edge cases in a compact sequence. Every sentence contributes necessary context, with no repetition of the tool name or annotations.

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 a four-parameter calculator with no schema descriptions and an existing output schema, the description covers the formula, units, variable meanings, fluid restriction, and one edge case. It is sufficient to invoke correctly, though it omits practical validity ranges and error conditions.

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 0%, so the description must compensate. It does so by defining all four parameters: coefficient as dimensionless pipe roughness C, diameter/head_loss/length in metres, and S as head_loss divided by length. It does not provide typical C ranges or validation constraints.

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 the specific formula (Hazen-Williams, SI), the computed quantity (pipe flow Q), and the exact formula and units. This clearly distinguishes it from generic flow or Darcy-Weisbach tools without requiring 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?

It explicitly states the applicability domain — water pipelines — and the exclusion: do not use for other fluids. However, it does not name an alternative such as Darcy-Weisbach for non-water fluids or explain when one formula should be preferred over the other.

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