add_smart_object_slot_behavior_definition

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

Annotations cover the safety profile (readOnly=false, destructive=false, idempotent=false, openWorld=false), so the description needn't restate them. It adds useful context annotations cannot: the class is resolved by name at call time, the call persists the asset (the returned 'saved' flag implies a write to disk), and the side effect of making the definition Validate()-valid. It does not mention what happens to an existing behavior already on that slot.

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 action, then prerequisites, then validation semantics, then the return shape. Four compact segments with little waste, though the inline class example partially duplicates the schema's own example.

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 correctly compensates by spelling out the return fields (definition_path, slot_index, behavior_class, behavior_count, saved). For a mutating tool whose annotations already carry the safety profile, the remaining gap is the unspecified behavior of the optional slot_index (default/target slot) when omitted.

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 description coverage is 100%, so the schema already documents all three parameters, including the short-vs-/Script class naming convention. The description's 'class resolved by name' and example class merely echo the schema. Baseline 3 is appropriate; it clarifies that slot_index is a slot of a definition but not what happens when the optional slot_index is omitted.

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 and resource ('Attach a behavior definition ... to a slot of a USmartObjectDefinition') and names the concrete target type, so an agent can tell it apart from remove_smart_object_slot_behavior_definition. The parenthetical '(or a default)' gestures at add_smart_object_definition_default_behavior but never names that sibling, so the differentiation is implicit rather than explicit.

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?

Gives real prerequisites — the class must derive from USmartObjectBehaviorDefinition — and explains the outcome that motivates the call: a behavior on every slot (or a default) makes the definition Validate()-valid. It stops short of naming the alternative tool for default-level behavior or stating when not to use this one.

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