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

With no annotations, the description carries the full burden and does well: it discloses the critical safety trait ('never charges a card'), explains that the human approves payment via pay_url, and specifies the return shape including the verbatim line to say. It omits stock reservation behavior, pay_url expiry, failure modes, and idempotency, which keeps it from a 5.

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?

Four tight sentences, front-loaded with the 'USE THIS' trigger, then what happens, the payment-safety boundary, and the required verbatim delivery of the returned line. Every sentence carries operational weight with no filler.

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?

For a simple three-parameter creation tool with no output schema, the description covers the trigger, the mutation's scope (no charge), and the return artifacts, which is nearly everything an agent needs to call it correctly. The unexplained nested buyer fields and out-of-stock/failure handling are the remaining 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 description coverage is 0% across three parameters (including a nested buyer object with email and country), so the description must compensate and it does not — no parameter is mentioned at all. An agent learns nothing about qty defaults, buyer field purpose, or product_id expectations beyond what the bare field names imply.

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 states a specific verb and resource ('Creates the order') and adds the concrete return artifacts ('pay_url plus a ready-to-say sentence'). It implicitly separates itself from quote/search siblings via the 'human says yes to a specific item' trigger, though it does not name an alternative outright, keeping it just shy of a 5.

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?

Gives a crisp, actionable trigger: 'USE THIS when the human says yes to a specific item.' That clearly delimits the pre-purchase quote phase from order creation, but no explicit when-not-to-use or named alternative (e.g., quote_order) is provided.

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