add_anim_graph_node

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

With no annotations, the description carries the full behavioral burden and does reasonably well: it discloses the return value (the new node as get_anim_graph emits it), the error path (unknown node_type refused with the list of known types), the name-generation default, and the parent default (root state machine). It stops short of stating permission/auth requirements or whether the node can be undone.

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 purpose, then the return contract and error behavior, then a clean Args section. Given the 0% schema coverage, the length is justified; almost every sentence adds information an agent needs.

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 mutation tool with no annotations and a totally undescribed schema, the description covers purpose, arguments, defaults, and error behavior thoroughly. It even restates the return contract despite an output schema existing. The main residual gap is permission/undo semantics, which the sibling undo/redo tools make relevant.

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 0%, so the description must compensate and it does: it explains formats for all five parameters, including accepted id forms (number or digit string), case-insensitive RTTI/palette node_type names with concrete examples, the parent-id domain (state machine or blend tree), and the position array as [x, y] integer pixels.

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+resource ("Add a node to an anim graph") that an agent can readily distinguish from sibling operations like add_anim_graph_parameter, add_anim_graph_transition, and connect_anim_graph_ports. It does not explicitly name which sibling to prefer, but the resource is unambiguous.

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?

Usage is implied by the description (you call it to create a new node, with node_type/parent_id selecting what kind and where). However, there is no explicit when-to-use guidance, no mention of set_anim_graph_node for modifying an existing node, and no exclusions. It leaves the routing to inference.

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