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

Annotations already declare readOnly, idempotent, non-destructive and open-world, so the safety profile is covered. The description adds genuinely new behavioral context: nothing is stored, each fact carries status/source/date, and coordinate queries are scope-limited. Return shape is signalled without duplicating the output schema.

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 sentences, front-loaded with what the tool returns, then the mode caveat. Dense with semicolons but nearly every clause carries new information; the 'information, not legal advice' and 'nothing is stored' clauses are short, purposeful disclaimers.

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?

An output schema exists so return values need not be re-explained, and the description still previews the result fields usefully. For a four-parameter, zero-required tool the main gap is the undocumented communeName and the lack of any statement about what happens when neither identifier is supplied.

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 only 25%, with just parcelRef documented, so the description must compensate. It does explain the lat/lng vs parcelRef semantic difference well, but communeName is left entirely unexplained in both schema and description.

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 ('Luxembourg plot check') from either a parcelRef or lat/lng, and enumerates exactly what comes back: PAG zoning, buildable envelope, buildings/planning, flood and heritage constraints. This is clearly distinguishable from the pricing, mortgage and listing siblings.

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 explicit mode-selection guidance: coordinates yield location-scope context only, while parcel identity and buildable figures require the cadastral reference. It also sets the expectation that output is informational, not legal advice. It does not, however, point to any sibling tool for related questions.

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