instance_create

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

With no annotations provided, the description must carry behavioral disclosure. It clearly conveys that this is a creation (write) operation that can set initial properties and attributes. However, it does not disclose behavior on invalid className, missing parent, property type mismatches, or whether any existing objects are affected. These gaps are notable for a creation tool without annotation support.

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?

A single, front-loaded sentence with zero filler. It names the operation, the object type, the parent requirement, and the optional payload efficiently.

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?

Given that the schema documents all parameters well and the description communicates the core behavior, this is adequate for basic invocation. However, there is no output schema and no annotation coverage, and the description does not specify the return value or error semantics (e.g., what happens if the parent path is invalid or the className isn't creatable). This leaves the agent to guess at failure behavior.

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 all six parameters have meaningful descriptions already. The tool description merely restates 'initial properties and attributes,' which mirrors the schema's own wording and adds no extra parameter-level meaning. Baseline 3 is appropriate.

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 ('Create') and resource ('new Instance of any valid Roblox ClassName'), and mentions the parent context and initial properties/attributes. This clearly distinguishes it from sibling tools like instance_clone, instance_reparent, and property_set, which operate on existing instances.

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?

The description implies the tool is for creating new instances from scratch, but it does not explicitly state when to prefer it over alternatives (e.g., instance_clone to duplicate an existing instance, property_set to modify properties after creation). With many siblings, the lack of explicit when-to-use guidance leaves some inference burden on the agent.

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