apple_create_subscription_group

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

With no annotations, the description carries the full behavioral burden. It usefully flags 'External action' (a real App Store write) and explains the per-group free-trial consequence, but it omits permissions/auth requirements, whether the operation is reversible, and how re-running against an existing group behaves. Some value added, but significant gaps remain.

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?

Front-loaded with the action in the first sentence, followed by the two clarifying facts (name semantics, per-group trial behavior). Every sentence carries information and none is filler, though the length is at the upper end of what this tool needs.

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 no explanation, and the description covers the core naming and group/trial semantics. The main omissions are the meaning of the 'locale' parameter and any setup prerequisites, minor against an otherwise complete picture.

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 0%, so the description must compensate. It does define the two genuinely ambiguous params well ('reference_name' is internal, 'display_name' is customer-facing), but leaves 'locale' (with its pt-BR default) and 'app_id' undocumented, so half the parameters get no added meaning.

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 first sentence states a specific verb and resource ('Create a subscription group and its localization'), which is clearly distinct from the sibling apple_create_subscription that creates individual products. However, it does not explicitly name or differentiate from siblings, so an agent must infer the relationship to apple_create_subscription from entity semantics alone.

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?

The description makes the group's role clear ('Every subscription product lives inside a group') and explains that free-trial eligibility is per-group, which implies this is a foundational setup step. But it never states when to call it versus alternatives, nor any prerequisite ordering relative to apple_create_subscription or apple_set_subscription_price.

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