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

Beyond the readOnlyHint annotation, the description discloses useful behavioral nuances: federal states are flagged subnational, no country-wide answer is inferred, rules change without notice, conveyancing runs through licensed local professionals, and the output is information rather than legal/tax/investment advice. This significantly enriches what the annotations alone convey.

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 description is dense and long, but nearly every clause adds a distinct legal dimension, usage caveat, or scope clarification. Scope is front-loaded in the first line, and the final disclaimers earn their place given the legal nature of the tool.

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 one-parameter, read-only tool with an output schema, the description is comprehensive: it names the legal areas covered, explains jurisdiction-level invocation, notes federal-state nuances, warns about changing rules, and sets expectations with disclaimers. An agent has enough context to select and call it correctly.

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?

The schema already documents cc as an ISO alpha-2 country code with 100% coverage, so the baseline is 3. The description adds optionality semantics not present in the schema: pass cc for one jurisdiction, omit it for the covered list. This is meaningful extra guidance, though the 'covered list' itself is not enumerated.

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 identifies a specific resource—real-estate law for foreign buyers in a jurisdiction—and enumerates concrete legal topics such as freehold restrictions, approval regimes, taxes, and inheritance. It also differentiates itself from listing-oriented siblings with 'The law behind a purchase, not listings,' making the tool's purpose unmistakable.

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 gives clear invocation guidance: 'Pass cc for one jurisdiction; omit for the covered list,' and explains how federal states are treated subnational rather than as a single country-wide answer. It includes an exclusion ('not listings'), but does not explicitly name an alternative sibling tool to use when listings are needed.

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