add_route

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

With no annotations provided, the description fully carries the behavioral transparency burden. It discloses that the route is loaded from the connected dev server, displayed as a live frame, and returns a route ID. It also explains auto-positioning, horizontal stacking, and the behavior of adding duplicate routes at different widths for responsive comparison.

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 description is well-structured with a clear main statement, bulleted constraints, and a separate responsive comparison note. Every section earns its place, and there is no redundant or filler content.

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?

Despite having no output schema, the description explicitly states that the tool returns the route ID. It covers purpose, restrictions, positional defaults, width labels, and a non-obvious use case (adding the same path multiple times for responsive comparison). This is a complete and self-sufficient description for an add-route tool.

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?

Although schema coverage is 100%, the description adds substantial meaning beyond the schema: it constrains paths to start with '/', explicitly prohibits full URLs, defines standard viewport widths, and explains how omitted x/y coordinates lead to horizontal stacking. This operational guidance is not present in 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?

The description uses a specific verb and resource: 'Add a web page route to the Design Canvas.' It clearly distinguishes this tool from siblings like list_routes, remove_route, and capture_canvas by describing its unique purpose of adding a live frame to the canvas.

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 gives clear usage context: routes are loaded from the dev server and displayed as live frames, with explicit constraints on path format, width standards, and auto-positioning. It also provides a concrete responsive-comparison workflow. It does not explicitly name sibling alternatives or state when not to use it, but the intended use case is well conveyed.

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