add_anim_graph_transition

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

No annotations are provided, so the description carries the full burden, and it delivers well: it discloses the return shape (transition object as get_anim_graph emits it), the undo grouping ('all conditions added as one Animation Editor undo step'), and refusal behavior ('an unsupported attribute is refused with the supported list'). It omits any permission/auth prerequisites, which keeps it from a 5 for a mutation tool.

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 one-line purpose, then a constraints paragraph, then an Args block keyed to parameter names. Despite covering 10 parameters, every sentence carries load (constraints, enums, example, refusal semantics) with no filler.

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?

For a 10-parameter mutation tool with zero annotation coverage, the definition supplies the invariants (shared parent, exit-node restriction), the wildcard path, enum legends, condition-type enumeration, and undo semantics. An output schema exists and is correctly referenced rather than re-explained, so nothing an agent needs to invoke it correctly is missing.

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 0%, so the description must compensate entirely, and it does: the Args section documents all 10 parameters, including enum value mappings (sync_mode 0/1/2, interpolation 0/1), priority range, blend_time units, and a full condition-type taxonomy with a worked example JSON. This adds decisive meaning the bare schema cannot convey.

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?

The opening sentence names a specific verb+resource: 'Add a state-machine transition, optionally with conditions.' It is immediately distinguishable from sibling operations like set_anim_graph_transition (modify existing) and add_anim_graph_node (node, not transition). An agent can identify the exact artifact being created without opening a 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?

Gives concrete preconditions: source and target must share a state-machine parent, and an exit node cannot serve as a source. It also explains the wildcard branch (omit source_node_id). However, it never explicitly contrasts this with set_anim_graph_transition or states when NOT to use it, so it stops short of full when/when-not routing.

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