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

It discloses a real cost behavior the annotations do not: every call consumes one estimate from the monthly FreightFA allowance, which explains the idempotentHint=false and is critical for an agent deciding whether to retry or batch. It also notes the no-service case. It stops short of describing accuracy, validity period, or rate currency.

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?

Purpose and scope are front-loaded in the first sentence, followed by two short sentences covering the no-service outcome and the quota cost. No filler or restatement of the tool name.

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?

With no output schema, the description usefully frames what the estimate contains (drayage legs, line-haul, ramps used) and covers the no-service case and quota consumption. Minor gaps remain around pricing units/currency and whether the estimate is a single point or range, but the agent has enough to call it 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?

Schema coverage is 100% and origin/destination/weight are each documented there, so the baseline is 3. The description adds that the two places are U.S. origin/destination points for a door-to-door move, but says nothing about the weight parameter or accepted location formats 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?

States a specific verb+resource (estimate a domestic intermodal rate) and breaks the product into its components: origin drayage, rail line-haul, destination drayage, plus the ramps used. This clearly separates it from sibling estimators like estimate_rail_rate, estimate_truckload_rate, and estimate_ltl_rate.

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 scopes the tool to domestic U.S. door-to-door lanes and states it flags lanes without intermodal service, which implies when results are usable. However, it never explicitly says when to choose this over estimate_rail_rate or the truckload estimator, nor does it state a mode-selection rule, leaving the agent to infer the boundary.

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