calculate_water_bill

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

Without annotations, the description should disclose behavioral traits. It notes inputs and output, but does not mention side effects, permissions, or idempotency. As a compute tool, it is safe, but the description could be more explicit.

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 short and front-loaded with the action. It uses two sentences plus a reference. However, the mention of 'fixed fee, variable rate' is somewhat misleading and reduces efficiency.

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 simple compute tool with an output schema, the description provides usage context. However, it lacks details about the calculation formula (e.g., does it use tariff bands linearly?) and does not mention the default value for price_per_m3, leaving gaps.

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 coverage is 100%, but the description introduces terms not in schema ('fixed fee', 'variable rate') and mentions 'tariff bands' without alignment to actual parameters. This introduces potential confusion rather than adding clarity.

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 it computes a water bill from consumption and tariff bands, and mentions a specific use case (household budget). It references a related group of calculators, but does not strongly differentiate from siblings.

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 suggests using for household budget and points to list_bundles for related calculators, but does not explicitly state when to use this tool over alternatives or when not to use it.

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