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

Consistent with readOnlyHint=true, and it goes beyond the annotation by disclosing the underlying endpoint (POST /v1/rex/SystemValues/getCategoryValues) and the shape of what comes back (id and label pairs) in the absence of an output schema. It omits edge behavior such as error handling for an invalid list_name or whether results are ordered/paginated.

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?

Three short sentences with zero waste: purpose first, then the practical payoff of the ids, then the raw endpoint for traceability. Nothing is buried or repeated.

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 one-parameter, read-only lookup with no output schema, the description covers what it returns (id and label), the source of the argument, and why the result matters. Only failure modes and result ordering are left unaddressed.

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 100% and the single parameter is already documented as the list name sourced from rex_list_value_lists. The description adds a concrete example value (property_category) but does not explain the allowed pattern or what happens with a malformed name, so it stays at baseline.

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 and resource: retrieves the allowed values (id and label) of a single Rex value list, with a concrete example (property_category). It is distinguishable from rex_list_value_lists as the expansion step, but the description never names that sibling explicitly, relying on the schema's 'from rex_list_value_lists' note to disambiguate.

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 ids are what writes and criteria expect' implies the downstream use case (fetching valid ids before writing or filtering) but gives no explicit when-to-use/when-not, no mention of rex_list_value_lists as the prerequisite/alternative path, and no guidance on what to do with an unrecognized list_name.

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