add_material_parameter_collection_track

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

Annotations already declare the safety profile (readOnly=false, destructive=false, idempotent=false, openWorld=false), so the description does not need to restate them. It adds the '(asset-level, headless)' trait and indicates it requires an existing MPC asset, which is useful context. It does not disclose permission/auth needs, side effects on the sequence, or undo behavior.

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 purpose is front-loaded in one crisp sentence, followed by a compact return-shape dump. The return field list is dense but earns its place because no output schema exists. No filler prose.

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?

There is no output schema, so the description's detailed return object (including save_error and key/section counts) is genuinely necessary and present. Annotations cover the safety profile and the restricted 'bound to an existing MPC asset' requirement is stated. The one gap is usage/alternative guidance, which the description omits entirely.

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 the schema already documents all five parameters (frame, value, mpc_path, sequence_name, parameter_name) including their optionality and defaults. The description adds only the high-level notion that keying is optional; it contributes little syntax or meaning beyond the schema.

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: adding a Material Parameter Collection master track bound to an MPC asset, with an optional scalar key. This is distinguishable from the MPC-asset-mutating siblings (add_collection_scalar_param, set_collection_param_default) because it targets a Level Sequence master track. However, it does not explicitly name which sibling it is not, so it falls just short of the 5 tier.

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?

No when-to-use guidance is given. In a sibling set with dozens of add_*_track and MPC-parameter tools, the description never says when to pick this tool over, e.g., add_collection_scalar_param or add_weighted_value_track. The '(asset-level, headless)' note hints at context but sets no conditions or exclusions.

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