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

With no annotations at all, the description carries the full burden and does well: it discloses the upstream data source (OpenStreetMap), the metered cost (0.005 USD per call via x402), and the shape of the result (normalised address, postcode, city, municipality, coordinates). It omits failure behavior for unparseable addresses and any rate/limit context, which keeps it short of a 5.

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?

One front-loaded sentence that names the action, the output fields, and the cost, with zero filler. Nothing could be removed without losing information.

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?

No output schema exists, but the description effectively substitutes for it by listing the returned fields, and it also surfaces pricing and data provenance. What remains unstated is error behavior on invalid input, a minor gap for a single-input lookup 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 the single parameter documents itself as a free-text Danish address, so the description adds little beyond it. Its only marginal contribution is reinforcing the Danish domain constraint. Baseline 3 is appropriate for a one-param tool whose schema is complete.

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 two specific verbs (validate, geocode) against a specific resource (Danish address) and enumerates the returned fields, so it is unmistakably distinct from siblings like dk_company or dk_weather. An agent can route to it 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 purpose makes the intended use reasonably self-evident, but there is no explicit when-to-use, no when-not, and no mention of alternatives or prerequisites. The Danish-only scope hint is only implicit in the name and the phrase 'Danish address'.

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