Create subscription

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

Annotations only carry openWorldHint=true, so the description does real work by disclosing the two-step nature of the flow — a checkout action is returned and the mandate is not authorised until the customer completes it. That is valuable context absent from structured fields. Beyond it, nothing is said about idempotency of subscription_ref, retry behavior, provider-specific failure modes, or permissions, so the behavioral picture remains thin for a mutation tool.

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, zero filler: the first front-loads what the tool creates, the second immediately delivers the most consequential return behavior. Nothing is repeated from the title or the schema.

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 an 11-parameter, nested, open-world mutation with no output schema and only a single openWorldHint annotation, the description is under-built. It names the returned checkout action but omits prerequisites, provider-specific constraints, what happens on duplicate subscription_ref, and any notion of what a successful response contains beyond the action.

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 36% across 11 parameters with nested objects, so the description is expected to compensate — and it adds nothing about plan, provider, return_url, provider_plan_id, provider_customer_id, provider_options, or metadata. The one genuinely consequential note (total_count being required by Razorpay) lives only in the schema, and the description does not surface the provider-specific requirements an agent would trip over.

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 uses a specific verb plus resource ('Create a recurring subscription') and names the mandate mechanisms (UPI Autopay / card e-mandate), which is more detail than the title alone. It does not explicitly contrast with siblings such as payments_cancel_subscription or payments_create_payment, though the create/cancel distinction is reasonably self-evident from the name.

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?

There is no statement of when to choose this tool versus payments_create_payment or the other subscription-adjacent sibling, and no preconditions (provider configuration, prior customer creation, or whether a plan must exist first) are given. The only usage signal is implicit: the customer must complete a checkout action, which is described as an outcome rather than as guidance for selecting the tool.

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