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

Annotations already cover the safety profile, and the description adds real context: the exact return shapes for both modes, the full 'kind' vocabulary, and a provenance caveat that Flatsome's list is a shipped static map rather than a live registry — useful for judging staleness. It does partly restate the annotation ('its server marks it read-only'), which keeps it off a 5.

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?

Information-dense and front-loaded: purpose first, then parameters, then return shapes. The return-shape and kinds enumeration is lengthy and slightly interrupts flow, but nearly every clause carries decision-relevant information.

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 fully compensates by documenting both response shapes and the enum of field kinds. Together with the builder-mode rules and the mutual-exclusivity caveat, an agent has everything needed to call it correctly on the first try.

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 baseline would be 3, but the description adds meaning the schema lacks: 'type' switches the whole response mode rather than just filtering, and 'builder' becomes required when multiple builders are active. That is genuine semantic value beyond the property descriptions.

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?

Opens with a specific verb+resource ('Lists the element types of a page builder') and immediately names the three supported builders plus the second mode ('fields of one type'). An agent can tell this is the element-type discovery tool, not a read/write of a layout, 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?

Supplies a clear purpose context ('what a layout element can hold before you read or plan an edit') and explains the builder default and when the parameter becomes mandatory ('required when several are'). It stops short of naming alternatives such as the Elementor widget-schema tools that overlap it.

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