Get fuel mix

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 adds useful context such as 'row-capped' and the latest/history behavior, but it does not disclose the return format, error conditions, or timezone conventions. For a read-only tool, the safety profile is implicitly benign, but behavioral details remain incomplete.

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 two sentences, front-loaded with the main purpose, and contains zero redundant or filler content. Every word contributes to understanding the tool's function and primary usage.

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 has six parameters, no output schema, and no annotations, the description covers the core functionality and the main behavioral switch (latest vs history). It leaves the exact return shape and row-limit interpretation to the schema, which is adequate for a tool of this complexity but not exhaustive.

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 schema already documents all six parameters and their details. The description adds a small amount of behavioral context for the 'latest' parameter and row-capping, but it does not materially extend understanding beyond the schema's property descriptions.

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 states 'Generation by fuel type (MW) for a US ISO' which clearly identifies the resource and data returned, though it lacks an explicit verb like 'returns' or 'retrieves'. It distinguishes get_fuel_mix from sibling tools by specifying fuel mix, which is a unique data type among the listed siblings.

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 explicit usage guidance: 'Use latest=true for the newest snapshot; otherwise returns recent history (row-capped)'. This clarifies the primary decision point for using the tool. It does not explicitly contrast with sibling tools, but the unique data type makes the usage context clear.

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