Get sub-elements

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

Annotations already declare readOnly/idempotent/non-destructive, so the safety bar is low. The description adds genuinely non-obvious behavior: passing a sub-element GUID returns its owner (bidirectional lookup) and the returned part GUIDs are valid inputs to three other tools. It does not discuss error behavior or empty results, but the cross-tool contract is valuable context beyond the annotations.

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?

Front-loaded with the core purpose, then the type taxonomy, then the cross-tool contract. It is dense and enumeration-heavy, but nearly every clause carries information an agent needs; the per-part field notes (className, begin/end, hidden flags) are the only slightly padded portion.

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 no output schema, the description carries the burden of describing returns and does so by naming the type-specific fields each part carries. The `elements` cap of 100 and default of 500 parts per type are documented in the schema, so nothing critical is missing, though ordering and empty-result behavior are 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%, so 3 is the baseline, but the description adds real meaning for the `types` parameter by mapping the enum values into their parent hierarchies (CurtainWall → Segment/Frame/Panel/Junction/Accessory, Stair → Riser/Tread/StairStructure, etc.), which helps an agent pick valid values rather than treating them as a flat list.

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 precise verb+resource ('get sub-elements') and enumerates the exact hierarchical element families and their part types, which immediately distinguishes it from siblings like get_element_details or get_element_components. An agent can tell what this returns without opening the schema.

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 implies usage by explaining that part GUIDs feed get_element_details, get_element_quantities and get_element_3d_geometry, and that a sub-element GUID returns its owner. However, it never states when to choose this tool over the similar get_element_components or get_element_details, nor any exclusions or prerequisites.

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