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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and non-destructive, so the safety profile is covered. The description adds real return-content context (that the response includes the data source and a Europe-only CEE17 connector), which helps an agent interpret results but stops short of noting coverage gaps or data freshness limits.

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?

A single dense sentence, front-loaded with the primary payload (plug types, voltage, frequency). The stacked parentheticals (IEC A–N, CEE17) make it slightly heavy but 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 read-only informational lookup with no output schema, the description is nearly sufficient: it names all returned facets and the location constraint on CEE17. It could note the geographic scope of other fields, but nothing critical to correct invocation is missing.

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 parameters are fully documented (ISO country code, locale enum), so the schema does the heavy lifting. The phrase 'for one country' mildly reinforces the country_code input but adds no syntax or format detail beyond the schema.

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+resource and enumerates exactly what is returned: plug types (IEC A–N), mains voltage, frequency, the value's source, and the CEE17 campsite connector. An agent knows precisely what it gets for a given country without opening the schema.

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 never says when to use this tool or what it is distinct from; there are no comparable siblings, but no usage context is given either. It relies entirely on the name to convey intent.

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