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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, so the safety profile is covered by structured data. The description adds the geographic/domain scoping (Danish grid operator) that explains why bounds exist, but discloses nothing about rate limits, failure modes, or what is returned on an unmapped coordinate.

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 short sentences, front-loaded with the action and resource, followed by the reason it matters and a trigger phrase. There is no redundant restatement of the tool name or schema fields.

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 simple two-parameter read-only lookup with full schema coverage and rich annotations, the description supplies enough intent and domain context to call it correctly. The only gap is that it never hints at the return value (the netselskab name), which matters since no output schema exists.

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% with both parameters documented as WGS84 plus min/max bounds, so the schema already carries parameter meaning. The description only restates latitude/longitude at a high level and adds no format or precision guidance beyond the schema, making the baseline 3 appropriate.

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 names a specific verb and resource ('Look up the Danish net company (netselskab)') and keys it to the exact lookup inputs ('for a location by latitude/longitude'), so an agent can tell it apart from the pricing siblings without opening the schema. It also supplies the domain term netselskab, which aids matching to Danish user phrasing.

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?

It gives a clear triggering context — 'needed to compute the exact total price for an address' — plus a literal user query example, so the agent knows when this precedes a price calculation. It stops short of naming an explicit alternative or stating when not to use it, and it does not mention fallback behavior for out-of-Denmark coordinates.

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