get_api_operation

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

Consistent with readOnlyHint=true. Beyond the annotation, the description discloses return-shape limitations an agent would otherwise discover the hard way: only direct input type definitions are returned and nested types are not expanded, and the metadata does not guarantee permissions or runtime support. That is real behavioral context, not restated safety hints.

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?

Four short sentences, front-loaded with the pull operation and its scope, then limits, then the caveat — no filler. Slightly reduced by heavy jargon packing ('CSDL', 'facets') with no expansion, which costs an unfamiliar agent a re-read.

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?

There is no output schema, and the description does shoulder that burden by describing what is returned (direct input type definitions) and what is truncated (nested types). With 7 parameters including alias pairs and a nested binding object, the description covers the main semantics; only overload-disambiguation guidance and how to act on the results are left implicit.

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 86%, so the baseline is 3, but the description adds genuine meaning beyond the schema: it explains what the nested 'binding' object accomplishes (narrowing signatures by entity set) and frames is_function as the Action/Function selection. Only signature_id disambiguation is left to the schema text, which already covers it well.

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: read the service CSDL to inspect Action/Function overloads, parameter types/facets, binding and import names. That scope is clearly narrower than the entity-metadata siblings (get_entity_metadata_summary, list_all_entity_definitions), but it never names the invocation counterpart call_d365_api_action, so the discovery-vs-invocation split has to be inferred.

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?

'Optional entity-set binding narrows signatures' hints at how to disambiguate, and the closing caveat ('read-only metadata does not prove permissions/runtime support') hints that verification requires an actual call. However, it never says explicitly when to use this instead of call_d365_api_action or the other metadata inspectors, so routing remains implied.

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