memoryos_get_billing_subscription

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It explicitly states the tool is read-only and enumerates what it never does, which is exactly the kind of side-effect transparency an agent needs before invoking a billing-related 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?

The description is two tight sentences with the primary action front-loaded and no wasted words. The side-effect clarification earns its place by reinforcing the read-only nature without redundancy.

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 zero-parameter read-only tool, the description is nearly complete: it states what is fetched and what side effects are absent. It could go slightly further by clarifying the exact return shape or differentiating from list_billing_plans, but those are minor gaps for such a simple tool.

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?

The tool has zero parameters and 100% schema coverage, so the baseline is 4. The description adds no parameter-specific detail, but none is needed because the input schema is empty.

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 resource: 'Fetch the authenticated tenant's read-only subscription and plan limits.' It clearly communicates what the tool does, though it does not explicitly differentiate itself from the sibling memoryos_list_billing_plans, so it misses the top score.

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 provides clear context and explicit exclusions: 'never creates a checkout, verifies a payment, or changes billing.' This helps an agent avoid using it for side-effectful billing operations, but it does not explicitly name alternatives or state when to prefer sibling tools.

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