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

Annotations already declare readOnlyHint, idempotentHint, and openWorldHint, so the safety profile is covered. The description adds only the defaults (today, a price zone) and confirms a full 24-hour set; it says nothing about response shape, units, or what happens for future dates beyond the forecast horizon.

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 compact sentences with the core capability and default front-loaded, followed by a query-matching hint. No filler, though the quoted Danish phrase is the only slightly loose element.

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?

The tool is simple and annotations cover safety, but there is no output schema and the description never characterizes the 24 returned entries (hour + price, currency). For a data-retrieval tool that gap is a real, if modest, omission.

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% and both enums are fully documented in the schema, including the four pricing modes. The description's mention of date defaulting to today merely restates the schema, so baseline 3 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?

States a specific verb and resource with scope: 'Get all 24 hourly electricity prices for a given date ... in a price zone.' The 'all 24 hourly' wording implicitly separates it from get_current_price (single price) and get_cheapest_hours, but no sibling is named explicitly.

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?

Offers a usage cue by quoting the Danish phrasing 'elpriser i dag / time for time', which helps match natural-language queries. However, it gives no explicit when-not guidance and never points to get_current_price, get_price_forecast, or get_european_prices as alternatives.

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