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

Annotations already declare this as a safe, idempotent, non-destructive read, so the safety profile needs no restatement. The description adds return-value behavior that annotations cannot convey — each rule carries a status, an applicability scope, and a next relevant date, plus upcoming deadlines — which meaningfully sets expectations for the response.

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 functional sentence is front-loaded and dense with useful detail; the trailing country list is long but is the one piece of information an agent cannot get from the schema. Slight penalty because that list dominates the text and would arguably serve better as schema enums.

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?

With a single fully-described parameter and no output schema, the description supplies the missing half: what a result record contains (status, applicability, next date) and that upcoming deadlines are included. Nothing an agent needs in order to call this tool correctly appears to be 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 coverage is 100% and only one parameter exists, so baseline would be 3; however the description enumerates all 29 accepted country values, which the schema does not (its only hint is 'A European country, e.g. Germany'). That enumeration closes a real risk of invalid input, though it gives no formatting guidance such as casing or name variants.

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?

Names the specific resource (national and EU rules for building and running a data centre) plus the scope ('in one European country') and the sub-topics covered (energy efficiency reporting, waste heat, permitting, grid). It is distinguishable from siblings like data_centre_market_overview or grid_connection_status without opening either 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?

Usage is only implied by the content: an agent can infer this tool answers 'what rules/deadlines apply in country X' rather than 'what is the market/grid doing'. There is no explicit when-to-use statement, no exclusions, and no routing to the sibling tools.

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