set_country

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

With no annotations, the description must carry the behavioral burden, and it does disclose one important downstream effect: payouts and the USDG-only rule for US, CA, GB, CH. It omits permissions, whether the value is overwritable/idempotent, and error behavior for invalid or unsupported codes, leaving real gaps for a mutation tool.

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 tightly packed sentences: the action and its format come first, then the precondition and payout caveat. No filler or repetition of the schema.

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 single-parameter, no-annotation, no-output-schema tool, the description covers what it sets, the expected format, when it is required, and a downstream payment consequence. Remaining gaps (reversibility, invalid-code handling) are minor but real.

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 description coverage is 0% and the only parameter is documented only by a regex pattern. The description compensates by naming the expected value ('ISO code like ID, NL, SG'), which is exactly the semantic detail the schema lacks, though it does not explain what happens with an unsupported code.

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?

Specific verb ('Declares') plus resource ('the country of the person or business running this agent'), with concrete format examples (ID, NL, SG). It is clearly distinguishable from siblings like set_profile or get_my_account, which deal with broader identity data.

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?

Explicitly states a precondition: 'Needed before stock payouts.' That tells the agent when the call is mandatory. It stops short of naming alternatives or saying whether the value can be changed later, so it is clear context rather than full when/when-not guidance.

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