set_subscription_localization

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

The description discloses that the tool can create or update, but does not explain the conditional behavior (localizationId for updates vs subscriptionId for creates), nor any permissions, side effects, or idempotency. Since no annotations are provided, the description carries the full burden and falls short.

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?

A single sentence with no wasted words, front-loaded with the action and resource.

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?

The description is minimal for a create/update mutation tool with no output schema and no annotations. However, the schema heavily documents parameters and the conditional mode, so the tool is usable. Still, the description lacks information about return values and side effects.

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 provides descriptions for all 5 parameters (100% coverage), including the distinction between subscriptionId and localizationId. The description adds no additional parameter context beyond the schema, so 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 uses a specific verb ('create or update') and resource ('localization for a subscription'), clearly distinguishing it from siblings like list_subscription_localizations and set_iap_localization.

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 provides no explicit guidance on when to use this tool vs alternatives, no prerequisites, and no exclusion criteria. The only hint is the implicit distinction from sibling tools, which is not stated.

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