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

Annotations already establish read-only and non-destructive behavior, and the description adds substantial operational nuance: the rolling 30-day window, that published OR downloaded stories both count, that BYO/publish_post posts never count, and that resetAt is authoritative rather than calendar months. These are exactly the non-obvious behaviors an agent must know.

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 dense but efficient: no filler, and the most important scope ('Plan tier plus metered usage') is front-loaded. The long comma-separated list could be more scannable, but every sentence earns its place.

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?

With no output schema, the description carries the burden of explaining what the tool returns, and it covers plan tier plus all metered fields and key counting rules. It could be more complete about response shape or value formats, but an agent has enough to invoke and interpret the result.

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%, including a detailed instruction set for context, so the baseline applies. The description does not add anything about the handle or context parameters; it only describes the output domain.

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 states a specific verb ('get') and resource ('plan usage'), then enumerates exactly which metrics are returned: AI stories, reels budget, BYO publishes, and publish streak. It is unmistakably about usage rather than generic tenant info, though it does not explicitly distinguish itself from the sibling get_billing_status.

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 content implies the tool is for checking plan tier and metered usage, and the caveat about resetAt tells the agent not to assume calendar months. However, it gives no explicit guidance about when to prefer this tool over related siblings like get_billing_status, and no when-not-to-use conditions.

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