Create a subscription

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

Annotations already declare readOnlyHint=false and destructiveHint=true, so the safety profile is covered. The description adds genuinely non-redundant behavior: idempotency, automatic territory-availability side effect, and the Pro-tier requirement. It stops short of describing the response, keeping it at a 4.

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 tight sentences with zero waste; the core action and its key modifiers are front-loaded before the side-effect and tier notes.

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 14-parameter creation tool with no output schema, the description covers the essential behavioral facts (idempotent, auto territory setup, Pro requirement) alongside annotations that carry the safety profile. Only the absence of any return/confirmation detail keeps it from a 5.

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%, so all 14 parameters are documented in the schema itself. The description mentions the group, USD price, free trial, and territory behavior, but adds no syntax or format detail beyond what the schema already provides, 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?

The description gives a precise verb (Create), resource (auto-renewable subscription), and scope (inside a group, USA price, optional free trial), so an agent immediately knows what the tool does. It does not explicitly differentiate from the nearby create_iap sibling, which is the only gap keeping it from 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?

There is no guidance on when to use this tool versus alternatives such as create_iap, nor any when-not/exclusion. The only contextual hint is 'Pro feature,' which signals a tier prerequisite but is not usage direction.

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