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

Beyond the readOnly, openWorld, and idempotent annotations, the description adds useful behavioral context: results are official prices, sorted from cheapest to most expensive, and include the station sign, address, and publication date. This helps the agent set expectations without contradicting the annotations.

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, information-dense sentence that front-loads the core purpose and then adds ordering and output-field details. There is no filler, repetition, or unnecessary explanation.

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?

Because there is no output schema, the description adequately covers the return content, including station sign, address, and publication date, plus the sort order. The schema covers parameters and limits, so the overall definition is sufficiently complete for a read-only list tool, though open-world variation is not explained.

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 input schema already documents all three parameters with 100% coverage, including accepted fuel codes, common names, limit constraints, and query semantics. The description adds no parameter-level detail beyond referring to a specific fuel, so the schema carries the burden and the baseline score applies.

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 that the tool returns official fuel prices at Alicante gas stations for a specific fuel, sorted from cheapest to most expensive, and that results include station sign, address, and publication date. It is specific about the resource and scope, though it does not explicitly differentiate itself from sibling tools.

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 implies the tool is used for fuel-price lookups in Alicante and emphasizes that it applies to a specific fuel, but it gives no explicit when-to-use or when-not-to-use guidance. No alternatives are mentioned, so the intended context is inferable rather than stated.

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