get_distinct_values

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. 'List' implies a read operation and the free-text/Armenian note is useful, but it does not disclose the output format, ordering, limits, or how layer context is resolved among layer_id, layer_key, and service_path.

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 sentence that front-loads the core action and uses an example to clarify. It is reasonably concise, though the parenthetical and example add more length than strictly necessary.

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 five parameters, 20% schema coverage, no annotations, and no output schema, the description leaves important gaps: how the layer is identified, whether 'where' is supported meaningfully, and what the return value looks like. An agent gets enough to know the intent but not enough to invoke it confidently without additional inference.

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 coverage is only 20%: the description covers 'field' implicitly but says nothing about 'where', 'layer_id', 'layer_key', or 'service_path'. The description does not compensate for the low schema coverage by explaining how to specify the target layer or apply filtering.

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 states a specific verb and resource: 'List the distinct values of one field.' It also gives concrete examples (land-use types, districts) that make the tool's purpose immediately recognizable and distinguish it from sibling tools like count_features or aggregate.

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 clearly identifies when to use this tool: to discover exact Armenian free-text categories before filtering on them. It provides helpful context but does not explicitly name alternatives or state when not to use it.

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