move_to_contact

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

With no annotations, the description carries the full burden and does well: it discloses that children move with the object, that overlapping parts produce no movement, that the whole object moves rather than just one end, and gives a practical depth range (0.005..0.02 for limbs and necks). It stops short of stating coordinate space, failure behavior, or whether the move is undoable/recorded.

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 core action is front-loaded and every sentence carries information, but the passage is long and packs several conditional behaviors and alternatives into one dense block, which slightly reduces scannability.

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 4-parameter mutation tool with no annotations and no output schema, the description covers semantics, side effects on children, no-op conditions, and alternatives. The main gap is return/confirmation behavior and any failure modes, which an agent might want before invoking.

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, and it does for all four parameters: `a` (object plus its children), `to` (the target whose surface is matched), `axis` (restricts sliding so other coordinates stay fixed), and `depth` (metres of sink with recommended values). This is far more than the bare schema conveys.

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 and resource ('Move `a` (with children) until its surface touches the surface of `to`') and precisely delimits the operation from neighbors like attach (bounding-box alignment) and combine (mesh merging). An agent can identify the tool's job without reading the 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 explicit conditional behavior for each parameter mode ('without axis it takes the shortest way; with an axis it slides along that axis only') and names concrete alternatives for cases it doesn't handle ('resize it with set_dimensions and anchor, or rebuild it with limb'). The no-op case (already overlapping) is also stated.

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