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

No annotations are provided, so the description carries the burden. It helpfully discloses provenance behavior ('every rate carries its source URL and the date it was read'), which is real value beyond structured fields. It does not state read-only nature, caching/freshness semantics, or whether rates are live versus published snapshots.

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 with zero filler, front-loading the resource and enumerating the three rate categories before adding the provenance detail. Every clause 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?

With no output schema, the description must cover return values and does so well by naming the three rate families and the provenance fields. It falls short of full completeness only on data format and freshness/liveness, which an agent might still wonder about.

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 tool takes zero parameters, so there is no parameter semantics to clarify; baseline 4 applies. No syntax or filtering detail is needed or expected.

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 ('Return') and a specific resource (the Dubai/UAE rate card with RTA minimum fares, Salik toll rates, fuel prices), so the agent knows exactly what data arrives. It does not explicitly differentiate itself from siblings like compute_cost or list_sources, leaving the boundary to inference.

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 phrase 'this service computes with' implies this is the data behind compute_cost, giving implied usage context. However, there is no explicit when-to-use, when-not-to-use, or named alternative guidance.

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