Turkey Fuel Pump Prices

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

With no annotations, the description carries the burden. It discloses the data source (EPDK), refresh interval (every 6 hours), fuel types covered, and that output includes city averages plus min/max across brands. This is far beyond the minimal schema info and gives the agent a clear behavioral model.

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 a single well-structured paragraph. It front-loads the core action, then provides source, coverage, parameter use, refresh, and examples in a logical order. Every sentence contributes value without excessive length.

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 simplicity (one optional param, no output schema), the description is quite complete. It explains what data is covered, where it comes from, how to filter, when it refreshes, and example queries. It doesn't detail exact JSON structure, but that's less critical for a simple lookup tool.

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 schema already fully describes the only parameter (city) with enum and omission behavior. The description adds a slight reinforcement ('Pass city... or omit it to compare all four') but does not materially increase semantic understanding beyond the schema, so baseline 3 is appropriate.

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 clearly states the tool gets current fuel prices in Turkey in TRY per litre, with a specific verb ('Get') and resource. It explicitly distinguishes itself from sibling tools (gold, exchange rates, prayer times, earthquakes) by naming fuels, source, and scope.

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 gives explicit usage examples ('Use this for petrol price in Istanbul...') and explains the optional city parameter behavior. It doesn't mention alternatives, but the sibling tools are clearly different domains, so context is sufficient.

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