Subscribe a customer to an offer (write)

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

No annotations are present, so the description carries the full burden. It discloses the write nature, the draft-vs-active state semantics, that a draft grants no rights, and that the subscription is a copy of the offer. It does not mention permissions, billing side effects, or idempotency, but the key state behavior is transparent.

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?

The description is dense and efficient, with the core purpose and 'WRITE' marker front-loaded. Each sentence carries useful information about state, activation, or alternatives. The override sentence is a minor extra that could mislead, but overall the structure is clean.

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 create tool with no annotations and no output schema, the description explains the essential state model and routes to activation. It doesn't specify return values, error conditions, or prerequisite offer/customer states, but the combination of description and a fully covered schema is adequate for an agent to invoke it correctly.

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 100%, so the baseline is 3. The description adds meaning beyond the schema by explaining that the subscription is a copy of the offer and by describing the consequence of start_now (draft grants no rights). The mention of 'pass an override' is slightly confusing because no override parameter exists in the schema, but the added context is still useful.

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: 'Creates a ProAbono subscription linking an existing customer to an offer.' It also distinguishes itself from the hosted subscription workflow and from start_subscription, which activates a draft. An agent can immediately tell this tool apart from its 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?

Explicitly contrasts the API path with the hosted workflow a customer would use, defines when to set start_now vs leave the subscription in Draft, and points to start_subscription for later activation. Clear when-to-use and alternative routes are provided.

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