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

With no annotations provided, the description carries the full burden of behavioral disclosure. It explains how each mode works (phone camera + A4 page for measurement, room photo for visualization), which goes beyond a simple surface-level description. It does not detail return values or error scenarios, but the tool's name implies it returns a URL, and the description is reasonably transparent for a simple GET-like tool.

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 concise and well-structured: two sentences cover the core purpose and mechanics, and a third sentence succinctly explains the parameters. There is no unnecessary jargon or repetition, making it easy for an agent to quickly grasp the tool's function.

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?

The description covers the primary use cases, the mechanics of both modes, and the optional product_id. It does not explicitly describe the return value (URL) but the tool name covers that. For a tool with only two optional params and no output schema, this is sufficient.

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?

The schema already provides 100% coverage with clear descriptions for both parameters (mode and product_id). The tool description adds some context about the meaning of 'measure' vs 'visualize', but this largely restates the schema. Since schema coverage is high, the baseline of 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?

The description clearly states the tool's purpose: to surface the AR measurement tool or product visualizer for specific customer needs (measuring windows or previewing blinds). It uses a specific verb ('surface') and resource, and the focus on AR/visualization distinguishes it from sibling tools like get_product or configure_product.

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 for when to use the tool ('when a customer wants to measure their window or preview a blind in their room'), but it does not explicitly mention when not to use it or name alternative tools. This meets the 'clear context, no exclusions' criteria.

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