migrate_base_plan_prices

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 important behavior: this changes prices for paying users, Google notifies them, and increases may require opt-in. It also discloses an environment-flag gate. It leaves unstated whether the change is reversible and how propagation/latency affects outcomes.

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 short and front-loaded, leading with the operation and following with the user-facing consequence and the gate. The trailing inline object literal is dense and slightly hard to scan, but every element carries information not present elsewhere.

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 unannotated mutation tool with 6 parameters and no output schema, it covers the essentials: what changes, whose prices change, user notification, opt-in possibility, environment gating, and the shape of the complex required parameter. It does not address error behavior, partial-region failure, or how long propagation takes beyond the latencyTolerance parameter already in the schema.

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 67%, and the largest gap — regionalPriceMigrations, whose schema items are opaque objects with no field descriptions — is filled directly by the description, which documents regionCode, oldestAllowedPriceVersionTime, and the priceIncreaseType enum values with a concrete example. It adds little for productId, packageName, and latencyTolerance, which the schema already explains.

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 and scope: moving EXISTING subscribers on legacy price cohorts to the base plan's current price in given regions. It distinguishes this from a plain price edit (it targets existing cohort subscribers, not new sign-ups) and names the key input that scopes the operation (regions).

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?

It gives a clear applicability condition ('EXISTING subscribers on legacy price cohorts', 'in the given regions') and a prerequisite gate (PLAY_MCP_ALLOW_PRICE_CHANGES). It does not name sibling alternatives such as convert_region_prices or ordinary base-plan price updates, nor does it state when not to use it, so it falls short of explicit routing.

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