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

Annotations already mark the tool as read-only, idempotent, and non-destructive. The description supplements this with meaningful behavioral detail: `start` is inclusive while `end` is exclusive, the UTC default is stated, and timezone interpretation via `tz` is explained. It also gives a concrete calendar-month example, which goes well beyond the structured annotation data.

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 compact, front-loaded with the core purpose, and uses clear formatting to separate the `kind` options from the time semantics. The calendar-month tip is the only extra detail, and it is practical and relevant. No sentence is wasted.

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 output schema exists and annotations cover safety, the description explains most of what an agent needs: purpose, units, `kind` choices, time boundaries, and timezone handling. The main gap is the `aggregation` parameter, whose values and effect are never described, plus the format of `zone` is left to inference despite the `list_zones` sibling.

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 0%, so the description carries the burden of explaining parameters. It does explain `kind`, `start`, `end`, and `tz` clearly, including boundary and timezone semantics. However, it omits any meaning for `zone` and `aggregation`, and accepts having no enums for those fields, leaving the agent without guidance on valid aggregation values.

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 opens with 'Actual or forecast load (MW)' and immediately defines the key discriminator `kind = actual | forecast | both`. This names a specific resource (load) and a specific unit, clearly distinguishing it from sibling tools like `get_generation` or `get_day_ahead_prices`.

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 operational context: it explains that `kind` selects actual, forecast, or both, and explains the time window semantics. However, it never states when to prefer this tool over alternatives or when not to use it, leaving the choice to be inferred mainly from the resource name.

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