Create a new Claude Design project

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

The description adds useful behavioral context: Claude Design names the project from the prompt, attachments are used as design references, and it returns the new projectId. However, it does not disclose timing/side-effect behaviors like waiting for the build to finish or window visibility, which are influenced by parameters and not covered by annotations (since none exist).

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?

Three sentences, front-loaded with the main action, and each sentence earns its place: workflow, auto-naming behavior, and attachment usage. No wasted words.

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?

With 8 parameters, no annotations, and no output schema, the description covers the core workflow and return value (projectId) but omits details about wait/visible/timeout parameters. It is sufficient for a basic invocation but not a comprehensive reference.

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 63%, and the description adds meaning for a few parameters: 'pick a template' explains the template param, and 'design from them' clarifies attachments. Other parameters like wait, visible, and timeoutSeconds are not explained in the description, though the schema provides some detail. This is a minimal compensation.

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 clearly states the tool starts a brand new project from the home screen, with a specific workflow (pick template, describe, begin building). This distinguishes it from siblings like list_projects and delete_project, which operate on existing projects.

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 provides clear context that this is for starting a new project from the home screen. It does not explicitly exclude alternatives or state when not to use it, but the context is unambiguous enough for most use cases.

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