rb209_field_types

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

With no annotations, the description fairly discloses the important behaviors: it is a GET that returns the full list, the list is fixed, and it only returns data for countryId 3. It does not state what happens for other countryIds, but for a simple lookup this is a reasonable disclosure.

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 compact and front-loads the endpoint and purpose before the usage caveat and fixed values. Each clause contributes information, though the repeated em-dash style makes it slightly choppy.

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 GET with no output schema, the description is essentially complete: it names the endpoint, the returned concept, the fixed result values, and the countryId constraint. The only gap is an explicit description of behavior for countryId values other than 3, but that is implied by 'only returns data for countryId 3.'

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 only parameter, countryId, is not described in the schema, and schema coverage is 0%, so this is the only place to learn its meaning. The description ties countryId to the path and says data is returned only for 3, giving the agent a concrete value to pass. It could be more explicit that 3 is the intended/only useful input.

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 opens with the exact HTTP verb and path, and states the result is 'the full list of available field types.' This clearly distinguishes it from the singular sibling rb209_field_type, so an agent knows this variant returns the whole set.

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?

It explicitly advises 'You usually don't need this' because fieldType is fixed to three known values, and warns that data is only available for countryId 3. It omits naming a specific sibling to use instead, but the fixed values themselves tell the agent the look-up is unnecessary.

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