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

Annotations already indicate readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the tool's safety profile is known. The description adds behavioral detail beyond annotations: it returns hourly data in MW, includes both real-time and forecast values, and is scoped to 'today'. This gives the agent a concrete expectation of the data without repeating annotation info.

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?

Two sentences with no filler. The first sentence front-loads the purpose, units, and forecast comparison; the second lists example queries. Every clause earns its place.

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 zero-parameter, read-only tool with no output schema, the description tells the agent exactly what data to expect (hourly MW, today, real-time vs forecast) and typical use cases. It lacks only minor details (e.g., timezone or exact rolling window), which are not critical for correct invocation.

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 tool has zero parameters and the schema is empty, so the baseline is 4. The description correctly omits parameter details and instead focuses on the result set, which is the only meaningful semantic content for this parameterless tool.

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 a specific resource ('MISO real-time total load (electricity demand)') and a unique value ('alongside the medium-term load forecast... so actual-vs-forecast is directly comparable'). It clearly differentiates from sibling MISO tools (e.g., miso_lmp, miso_fuel_mix) by focusing on load and forecast comparison.

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 offers concrete example use cases ('MISO demand today', 'is MISO load running above forecast', 'peak-hour timing'), which tell the agent when to invoke this tool. It does not explicitly mention alternatives or exclusions, but the use cases are clear enough to route the agent appropriately.

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