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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds the requirement of NOMADSTAYS_MCP_AGENT_TOKEN, disclosing an authentication need beyond the annotations. It doesn't describe the return format, but for a list tool this is implied.

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 entire description is one sentence that front-loads the action ('List valid values') and includes only necessary information: the purpose and the authentication requirement. No wasted words.

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 zero-parameter, read-only tool with no output schema, the description fully covers what it does, what it's for, and the auth requirement. The annotations cover safety. This is complete for the tool's simplicity.

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 input schema is empty with zero parameters, so the baseline is 4. The description mentions cxPolicyId but that is a field in another tool, not a parameter here; no additional parameter documentation is needed.

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 uses the specific verb 'List' and identifies the resource as 'valid values for a Stay's cancellation policy', and further clarifies it pertains to the cxPolicyId field in updateStayOrganisationalData. This clearly distinguishes it from other options-list sibling tools like getRoomTypeOptions or getCountryOptions.

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 provides clear context by linking the output to the cxPolicyId field in updateStayOrganisationalData, indicating this tool is used when needing valid cancellation policy values for that update operation. It does not explicitly list when not to use it or name alternatives, but the purpose is specific enough to infer appropriate usage.

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