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

Beyond the annotations (free/synchronous confirmed, destructive=false), it discloses a lot: omitted keys stay unchanged, null clears the override, none disables a role, [] vs omitted hitboxFrames semantics, 64-window cap, hurtbox never inheriting the movement shape, and legacy collisionBody fallback. This is exactly the kind of context annotations cannot carry.

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 key operational fact ('FREE, synchronous metadata edit'), then dense, information-bearing sentences with almost no filler. It is long by necessity given the semantics, though a few clauses could be tightened.

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 complex nested schema with no output schema, the description covers mutation semantics, scope selection, and frame-window rules thoroughly. It omits any statement of the response/result, but for a synchronous metadata edit that gap is minor.

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% at the property level, so the description must compensate, and it largely does: it defines omitted/null/none for collisionRoles keys, scope defaulting, poseId vs animation exclusivity, and hitboxFrames format (inclusive zero-based indices, max 64, [] disables). The characterId parameter is left implicit, which keeps it from a 5.

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 description states a specific verb+resource: a 'FREE, synchronous metadata edit' that sets character movement, hurtbox and hitbox bodies. It is clearly about character-scoped collision roles as opposed to asset-scoped siblings. It never names the near-identical sibling set_asset_collision_roles to distinguish scope, so it stops short of 5.

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?

It gives concrete usage rules: scope defaults to character base, you select one poseId or animation, and only animation scope accepts hitboxFrames. There is no explicit 'when not to use' statement or direct routing to the asset-level alternative, so a strong 4 rather than 5.

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