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

Annotations already declare readOnly, idempotent, non-destructive, open-world behavior, so the safety profile is covered. The description adds genuinely useful provenance information — that beyond tomorrow the values are estimates rather than published prices — but says nothing about caching or refresh cadence. That is a meaningful but modest addition given the annotation coverage.

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, front-loaded with the core capability and the data-quality caveat immediately after. The Danish search phrase earns its place as a matching hint; nothing is redundant.

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?

There is no output schema, and the description does not say what the result looks like — hourly resolution, per-area arrays, units, or currency. It covers the temporal scope well but leaves the return shape underspecified for a series-returning tool.

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 coverage is 100% and both enum parameters are fully described in the schema, including what each mode costs and which zone maps to which region. The description only echoes "for a price zone" and adds no syntax or selection guidance beyond the schema, so the 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 (7-day electricity price forecast) plus the zone scope, and explains that today/tomorrow are actual day-ahead prices while later days are weather-corrected estimates. It implicitly separates itself from siblings like get_today_prices and get_current_price, though it does not name them.

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?

Gives a clear use context via the quoted Danish phrasing "elpriser de næste dage / prognose", which signals the multi-day query intent. It does not state when to prefer the short-horizon siblings instead, so the routing guidance is clear but not exhaustive.

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