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

Annotations already declare mutation, open-world, and non-idempotency. The description adds genuinely new context: this ships a physical kit to a US address and describes exactly what is in it. It omits duplicate-request or rate-limit behavior, which is minor here.

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?

Two short sentences, front-loaded with what the tool does, followed by the call condition. Nothing is padded or repeated from the schema.

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 tool's purpose and the US-only constraint are covered, and annotations carry the safety profile. However, for an 11-parameter request with no output schema, the description says nothing about the optional fields or what a successful submission yields, leaving real gaps.

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 coverage is only 27% across 11 parameters, and the description names no parameters at all. Optional fields like notes, industry, company and phone are left unexplained, so the description does not compensate for the coverage gap where it is expected to.

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?

Specific verb (mails) and resource (free Luxor sample kit) with contents spelled out (clear, frosted, solid white 30mil cards). It is immediately distinguishable from create_order and list_products, the nearest siblings.

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?

"Only call this when the user has asked for samples and provided their details" gives an explicit precondition gate. It does not name an alternative for users who want to buy, but the when-to-use condition is clear.

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