estimate_cost

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

With no annotations, the description carries the full burden. It discloses that the tool provides a 'quick cost estimate' and specifies input fields, but lacks details on side effects (none likely), rate limits, or error behavior. This is acceptable for a simple read-like tool.

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 short sentences, no filler, clear and front-loaded. Every word contributes to understanding the tool's purpose and input requirements.

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 estimation tool with an output schema, the description covers the essential input requirements and purpose. It doesn't mention the default currency or optional fields, but those are in the schema. Sufficient for an agent to use correctly.

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 already covers all parameters (100% coverage), so the description adds value by clarifying the minimum requirements for each part object (part_number and quantity) and noting the quick nature of the estimate. The addition of 'at minimum' provides nuance 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 'Get' and resource 'cost estimate', and specifies the required fields (part_number, quantity). It distinguishes from sibling tools like calculate_bom_cost or compare_prices by emphasizing it's a quick estimate.

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 provides clear input requirements (list of parts with part_number and quantity) and implies a quick, non-binding estimate. It does not explicitly state when not to use this tool compared to alternatives, but the context is adequate.

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