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

Annotations declare the safety profile (readOnly=false, idempotent=false, openWorld=true), but the description adds two things annotations cannot: that accept_terms must be true or the call fails, and that the api_key is shown only once (non-recoverable). That is meaningful behavioral context beyond the structured fields.

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?

Three short sentences, front-loaded with the core action and the hard gating requirement, then the address shape and the one-time key. Efficient, though the ship_to restatement duplicates the schema rather than earning its place.

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?

An output schema exists so return values need not be explained, and the description covers the critical validation and one-time-secret behavior. It omits prerequisites (no existing account required?), webhook/callback expectations, and how to recover or rotate the key, which would fully round it out.

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 100%, and the description's parameter text (accept_terms requirement, ship_to object shape) is verbatim-equivalent to the schema descriptions. It adds no syntax, constraint, or default information the schema lacks, so the baseline 3 applies.

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?

States a specific verb and resource ('Create an autonomous agent account and API key'), which clearly separates it from read-oriented siblings like get_account and from order-flow tools like create_checkout_link. It does not explicitly name or contrast with any sibling, so it stops short 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?

Usage is only implied: the tool is evidently the onboarding step that must precede order/quote tools, but the description never says when to call it versus get_account or what the prerequisite state is. No exclusions or alternatives are given.

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