distance_matrix

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

Discloses the 625-pair cap, a key behavioral constraint. No annotations provided, but description adds value by mentioning the limit. Does not mention rate limits or cost.

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, no fluff, front-loaded with core purpose. Every word 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?

No output schema, so description should clarify return format (e.g., units, structure). Mentions 'road distances and travel times' but not detailed enough for complex use.

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?

No parameters in input schema, so description has no need to explain them. Baseline 4 for 0 params; schema coverage is 100% trivially.

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?

Clearly states the tool computes road distances and travel times for origin-destination pairs, using free-text addresses or lat,lon. Distinguishes from siblings like directions (step-by-step) and traffic.

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?

Provides explicit use cases: fleet dispatch, nearest-depot, bulk ETA tables. Lacks explicit when-not or alternatives, but context implies directions for step-by-step.

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