get_eu_gas_price

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It transparently states that no API key is needed (auth), specifies units (EUR/MWh) and hubs (TTF/NBP), and indicates the data range (latest + daily history). It does not detail rate limits, response format, or error behavior, but for a read-only data retrieval tool, the key behavioral aspects are sufficiently disclosed. The 'Spark spread, gas-power switching' line is a minor ambiguity but does not contradict the core behavior.

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 concise and front-loaded: it starts with the core purpose ('EU gas prices'), then gives essential details in short, scannable phrases (hubs, history, no API key, spark spread). Every sentence contributes useful information, and there is no fluff or repetition of the tool name. It earns a perfect score for efficiency.

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 (2 parameters, enums, full schema coverage) and the absence of an output schema, the description does a good job of covering the key context: what data is available, the units, hubs, and the convenience of no API key. It mentions 'spark spread' and 'gas-power switching' which hints at additional derived data, though not fully elaborated. For a focused data-retrieval tool, this is reasonably complete, but could benefit from a bit more detail on the response structure.

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 covers both parameters (hub and period) with exhaustive descriptions, including enum values and units. Schema description coverage is 100%, so the baseline is 3. The tool description adds some context like 'EUR/MWh' and 'European benchmark' for TTF, but these are already implied in the schema for hub. No additional parameter semantics are provided beyond the schema, so a 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 identifies the tool's purpose: retrieving EU gas prices for TTF or NBP hubs. It specifies the resource (gas prices) and distinct hubs, which differentiates it from sibling tools focused on power grids, weather, or other energy data. The verb 'get' is implicit in the name, and the description enhances it with specific units and data granularity.

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 provides clear context about when to use the tool: for EU gas prices, with specific hubs (TTF/NBP) and time periods (latest/history). It also notes that no API key is required, which is a practical usage hint. However, it does not explicitly mention alternative tools or exclusion criteria, so it stops short of full guidance. The 'gas-power switching' mention implies a use case but not an explicit alternative.

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