add_anim_slot_group

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

Annotations already declare idempotentHint=true, destructiveHint=false, and readOnlyHint=false, but the description adds concrete idempotent behavior: an existing group returns added=false and changes nothing while the skeleton is still saved. It also discloses failure behavior, though it says 'success false' while the documented return field is saved, a minor internal inconsistency.

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?

The opening sentence is front-loaded and clear, but the description redundantly states return values twice ('Returns added and slot_group_count' followed by the full Returns object) and introduces a 'success false' phrase that does not match the named saved field.

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?

Given the annotations covering mutation safety and idempotency, plus an inline return object, the description is mostly sufficient. It explains the save outcome and return fields, though the success/saved wording mismatch and lack of detail about how montage slots are affected leave small gaps.

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 are already documented with examples. The description does not add syntax or meaning beyond the schema, which makes the baseline score of 3 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 specific verb (add) and resource (animation slot group) plus the target asset type (USkeleton) and save action. The parenthetical explains what a slot group is and the verb distinguishes it from remove_anim_slot_group and montage-slot tools.

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 gives clear context for what the tool does but does not explicitly say when to use it versus alternatives like add_montage_slot or remove_anim_slot_group. Usage is implied rather than guided with exclusions or prerequisites.

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