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

Annotations already declare readOnlyHint=true, openWorldHint=false and destructiveHint=false, so the safety profile is covered; the description adds the non-obvious operational requirement of NOMADSTAYS_MCP_AGENT_TOKEN and discloses the returned content (name and 2-letter code). It does not mention result ordering or size, but those are minor for a static reference list.

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 compact sentences, front-loaded with the purpose and the consuming field, with no filler or repetition of the title.

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?

With no output schema and no parameters, the description covers what an agent needs: the payload fields (name, 2-letter code), the field it feeds, and the auth prerequisite. Only the envelope format of the result (list vs. keyed object) is left unspecified, which is a small gap.

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 tool takes zero parameters and the schema is an empty object, so there is nothing for the description to disambiguate; baseline 4 applies.

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 (List) plus resource (valid values for a Stay's country) and the exact field it populates (countryId in updateStayOrganisationalData), which cleanly separates it from sibling option-listers like getCurrencyOptions and getStayTypeOptions.

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 reference to countryId in updateStayOrganisationalData gives clear context for when this tool is needed (before populating that field), but it does not state exclusions or name alternative sources of country data such as getStaysByCountry.

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