rb209_field_countries

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

The GET verb communicates a read-only operation, and 'full list' indicates no filtering or narrowing. With no annotations and no output schema, the description carries the burden, but it does not disclose response format, ordering, or potential error behavior. This is minimal but acceptable for a zero-parameter lookup.

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 a single concise sentence that front-loads the endpoint and immediately states the returned content. Every word earns its place with no redundancy.

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?

Given the tool has no parameters, no annotations, no output schema, and a very simple purpose, the description is sufficient for an agent to invoke it correctly. There is no missing input or filtering information that would leave the agent uncertain.

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?

There are no parameters, so schema coverage is trivially 100%. The description adds no parameter details, but none are needed; 'full list' reinforces that there are no input constraints. Baseline 4 is appropriate for a zero-parameter tool.

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 ('/api/Field/Countries'), the HTTP verb (GET), and the exact result ('the full list of available countries'). The plural 'list' clearly distinguishes it from the singular sibling rb209_field_country and other lookup tools.

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?

Usage is implied: an agent would use this when it needs the complete list of available countries. However, there is no explicit guidance about when not to use it or how it compares to the singular rb209_field_country or other country-related endpoints.

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