Get Fuel Surcharge

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

The annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is known. The description adds behavioral context beyond annotations by explaining how auto mode classifies carriers (UPS/FedEx/DHL as parcel, others as LTL) and that parcel history requires a service_level. No contradictions.

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 three sentences long, front-loaded with the primary purpose, followed by usage context, then key constraints. Every sentence carries useful information without redundancy or filler.

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?

Given the tool's moderate complexity (5 parameters, no output schema) and the presence of strong annotations, the description covers the main use cases, the auto mode logic, and special requirements for parcel history. The return format is implied by the purpose ('percentages'), so this is sufficient for an agent to select and invoke the tool 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%, so the baseline is 3. The description adds meaning beyond the schema by explaining the auto-mode mapping and clarifying the service_level requirement for parcel history, which helps the agent understand how parameters interact.

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 uses a specific verb ('Get') with a specific resource ('carrier-published fuel surcharge percentages') and scope ('LTL freight and parcel carriers'). It clearly distinguishes from all sibling tools, none of which cover fuel surcharges.

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 explicitly states when to use the tool ('Use when the user asks about current or historical fuel surcharge rates') and gives important guidance on auto mode and parcel history requirements. It doesn't name alternatives, but no direct alternative exists among siblings, so the guidance is clear.

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