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 activation behavior (trial immediate, paid pending), return of payment details, lack of auth requirements, and the second-trial refusal rule. This goes far beyond a generic 'place an order' statement.

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 sentences, each earning its place: the first states the action, the second explains behavior, the third gives a key constraint. Front-loaded with 'Place an order' and no redundant 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 4-parameter tool with no output schema, the description covers key behavioral aspects: trial vs paid outcomes, lack of required account/card, and the restriction on second trials. It doesn't detail return values fully but mentions payment details for paid plans, and likely relies on sibling tools like lease_status for follow-up.

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 50% (plan, country have descriptions; organization_name, billing_email do not). The description adds meaning for billing_email by linking it to the trial-refusal rule, and for plan via trial/paid distinction, but organization_name remains unexplained. It partially compensates but not fully.

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 opens with 'Place an order' and immediately clarifies it's for a lease/plan by discussing trial and paid plans. It distinguishes from siblings like list_plans and renew_lease because ordering is the primary purchase action, though it doesn't explicitly name alternatives.

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?

Provides clear context: trial activates immediately, paid stays pending, no account/card needed, and a second trial is refused—ordering a paid plan instead. This implies when to choose this tool over renewing or listing, but doesn't name sibling tools explicitly.

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