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

Annotations only declare readOnlyHint=false, idempotentHint=false, and destructiveHint=false; the description goes further by disclosing the critical behavioral boundary: 'Verified payment queues research for human-controlled execution and review; it does not authorize consequential action.' This tells the agent that the tool is a controlled side-effect action rather than a green light for execution, which is high-value safety context the annotations cannot convey. It does not mention other side effects (e.g., confirmation emails or stored session records), but the most consequential behavior is disclosed.

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 sentences, no filler. The first sentence front-loads the trigger condition before the action, and the second adds the essential behavioral boundary. Every clause earns its place, and the structure reads naturally for an agent skimming for when-to-call and what-happens.

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 conveys the workflow state (human agreed, payment verified), the scope (bounded offers), and the safety boundary (queues research, no consequential action), which covers the most important calling context. However, with no output schema and 10 parameters, it never hints at what the tool returns or what the caller should do next after 'preparing' the checkout, leaving a meaningful gap for a payment-related mutation.

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?

With schema description coverage at 0%, the description must compensate, and it adds real meaning for the two most important parameters: 'bounded FAIE Signal Brief or Proof Sprint' maps to the offer_key enum, and 'human explicitly agrees to pay' explains the user_confirmed_payment const:true requirement. However, eight of ten parameters (email, geography, question, use_case, request_id, organization, name, role) receive no semantic explanation in either the schema or the description, so it only partially compensates for the coverage gap.

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 names a specific verb and resource ('prepare the secure checkout') and attaches a clear precondition ('After the human explicitly agrees to pay'), which sharply distinguishes this action from the get-only siblings get_faie_offers and get_faie_order_status. It also scopes the checkout to the two offer types ('bounded FAIE Signal Brief or Proof Sprint'). An agent can tell exactly what this tool does and what it is not.

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 opening clause 'After the human explicitly agrees to pay' gives a concrete trigger condition for when to invoke the tool, and the phrase 'bounded ... Signal Brief or Proof Sprint' implies it should follow offer selection. It does not explicitly name the sibling tools as alternatives or state when-not-to-use conditions, but the precondition plus the boundary sentence provides clear usage context.

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