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

readOnlyHint=true already tells the agent this is a safe lookup, so the description only needs to add context. It adds the endpoint and the conditional input rule, but says nothing about what the price depends on (time, date, surcharges), what currency is returned by default, or how missing vehicle class is handled.

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?

Three short sentences, front-loaded with the purpose before the input rules. The trailing "GET /api/integration/pricing" adds little for an agent choosing a tool, but it takes no meaningful space.

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 seven parameters, no output schema, and only a readOnly annotation, the agent still lacks the shape of the answer (currency of the quote, whether it is a single price or a breakdown) and any precondition for a valid result. Adequate to attempt a call, not sufficient to interpret it.

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 every parameter is already documented including the source tools for currency_id and vehicle_class_id. The description restates the optionality of vehicle class and currency and adds the to-coordinates-or-distance choice, but that conditional is only weakly expressed and mostly mirrors the schema's own wording.

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 and resource ("Get the price for a trip") plus the scoping inputs (coordinates, vehicle class, currency), so the agent knows exactly what the call produces. It never names limoexpress_get_extra_fees_pricing, so sibling differentiation is left to the agent despite that tool sounding very close.

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?

"Give the destination coordinates, or a distance when there is no destination" is genuinely useful guidance on which input mode to pick. However, there is no statement of when to use this versus limoexpress_get_extra_fees_pricing, nor any prerequisite about validating vehicle_class_id or currency_id first.

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