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

With no annotations, the description carries the full behavioral burden. It does add genuinely useful context beyond structured fields — the read-only lookup nature and the per-call price ($0.005 USDC on Base) — but it says nothing about what happens when the city is unknown, ambiguously spelled, or not Iranian.

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 with the core action first, then usage, then return shape and price. Every sentence carries distinct information and nothing is redundant.

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?

For a simple single-lookup tool, the description covers purpose, usage, and the return values (city and province), which substitutes for the missing output schema. The gap is the absence of any failure/ambiguity behavior, which matters for a name-matching lookup.

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 description coverage is 100%, so the alias parameters (text, value) are already documented in the schema, and the description only restates that the name is Persian. It adds no guidance on the aliases, the fact that all three parameters are optional, or which to prefer, so it neither compensates nor regresses.

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 (look up), resource (Iranian city), and output (its province), which cleanly separates it from the sibling province/holiday/validation tools. It stops short of explicitly contrasting with the closest sibling, fa_iranProvince, so an agent must infer the direction of the mapping.

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?

Gives two concrete use cases — resolving a city inside an address and grouping a location by region — which is real when-to-use guidance. It never states when NOT to use it or names an alternative tool for related tasks, so the routing is implied rather than explicit.

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