ls_get_subscription_item_usage

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the description merely restates the read-only nature ('Get current usage'). No additional behavioral context (e.g., error handling, pagination, rate limits) is added beyond the annotations.

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 a single sentence that is concise and front-loaded with the key action and resource. No redundant information is present.

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?

Given the tool's simplicity (one read-only parameter), the description adequately covers purpose and scope. It does not document the return value, but the absence of an output schema is not critical for a straightforward usage check. Slightly more context (e.g., what the response contains) would improve completeness.

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?

There is only one parameter, subscriptionItemId, which is described in the schema as 'The subscription item ID'. The description does not add any extra meaning or context for the parameter. Since schema coverage is 100%, a baseline score of 3 is appropriate.

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 clearly states the verb 'Get', the resource 'current usage for a metered subscription item', and the scope 'within the current billing period'. This distinguishes it from sibling tools like ls_get_subscription_item (which likely retrieves item details) and ls_get_usage_record (which might fetch a specific usage record).

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 implies the tool is for checking current metered usage, but it does not explicitly state when to use this versus alternatives like ls_get_usage_record or ls_list_usage_records. No guidance on prerequisites or when not to use is provided.

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