google_create_subscription

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

With no annotations, the description carries the full burden, and it does disclose the most consequential behavior: base plans are created in DRAFT and are not purchasable until google_activate_subscription_base_plan is called. However, it says nothing about the Google Play edit-transaction lifecycle (google_create_edit / google_commit_edit siblings exist) or required permissions, which are real prerequisites 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?

Three sentences, each earning its place: purpose first, required payload second, resulting state and follow-up action third. No filler or repetition.

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 5-parameter mutation tool with a deeply nested schema and no output schema, the description covers the critical inputs and the post-creation state an agent must reason about. The remaining gap is the surrounding edit/publish workflow and authorization prerequisites, which an agent would need before invoking this in practice.

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 the schema already documents packageName, productId, listings, basePlans and regionsVersion in detail. The description restates the required shape ('listings and at least one base plan with billing details and per-region pricing') without adding format or constraint detail beyond what the schema provides.

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 ('Create a new subscription on Google Play') and scopes it to the monetization API, clearly separating it from sibling product-creation tools like google_create_one_time_product and google_create_iap. It also enumerates the required body shape, so the agent knows exactly what kind of object it is creating.

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 tells the agent what must be supplied (listings plus at least one base plan with billing details and per-region pricing) and routes it to google_activate_subscription_base_plan as the follow-up step. What is missing is an explicit exclusion — e.g. 'use google_create_one_time_product for non-recurring SKUs' — so it falls just short of the 5 benchmark.

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