calculate_fuel_cost

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

With no annotations, the description adds that it returns 'total cost and L used', but does not disclose error conditions, limitations, or any side effects. For a simple calculation tool, this 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?

Two sentences, front-loaded with purpose, no wasted words.

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 calculation tool with full schema coverage and an output schema, the description covers inputs, outputs, and usage context. It also references related tools via 'list_bundles', making it complete.

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 mentions the same parameters without adding additional semantics beyond the schema.

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 the verb 'compute' for 'fuel cost' and provides context (journey, trip budgeting, company expense). It references 'list_bundles' for related calculators, but does not explicitly differentiate from other calculation tools in the sibling list.

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 indicates when to use the tool ('Use for trip budgeting or company expense') and points to 'list_bundles' for related 'auto-transport' calculators, providing some exclusion guidance.

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