add_gameplay_effect_component

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

Annotations already declare readOnlyHint=false and idempotentHint=true, so the description isn't the sole source of the safety profile. It nonetheless adds real behavioral context the annotations do not: the write persists without triggering a recompile, and idempotency manifests concretely as already_existed=true rather than silently duplicating. It could say more about permissions or side effects on existing components, so not 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?

Three sentences plus a returns block, all front-loaded: action, idempotency guarantee, then workflow routing. Every clause earns its place and nothing is redundant.

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?

No output schema exists, so the description correctly inlines the return shape (path, type, class, count, added, already_existed), which is exactly what an agent needs to interpret success. Combined with the mutation/idempotency disclosure, the definition is complete for a 2-parameter write tool.

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 both parameters (component_type with its full bare-type enumeration, gameplay_effect_path) are already documented in the schema. The description adds only the implicit constraint 'of a standard type', which the schema's enumerated list already conveys. Baseline 3 is appropriate.

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 (add) + resource (one empty UGameplayEffectComponent) + target (GEComponents of a GameplayEffect Blueprint CDO) and even the persistence behavior ('save without recompiling'). An agent can distinguish this from remove_gameplay_effect_component, get_gameplay_effect_components, and the set_gameplay_effect_component_* family without opening any 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?

Explicitly routes the workflow: use set_gameplay_effect_component_* to configure the component after adding, and get_gameplay_effect_components to list existing ones. It also states idempotency semantics (existing type returns already_existed=true), so the agent knows re-invocation is safe. Alternatives are named and the condition selecting each is clear.

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