ls_create_usage_record

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

Annotations already declare destructiveHint=true and readOnlyHint=false, indicating mutation. The description adds context about the two action modes but does not elaborate on side effects, permission needs, or rate limits. With annotations covering the safety profile, a score of 3 is appropriate.

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?

Two sentences, no fluff. First sentence states purpose, second explains the key parameter. Information is front-loaded and every sentence adds value.

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 simple tool with three well-described parameters and no output schema, the description covers the essential usage (reporting usage with increment/set). It lacks details on error cases or idempotency behavior, but given the simplicity and annotations, it is mostly complete.

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?

Input schema has 100% description coverage. The description adds value by clarifying the 'action' parameter: it explains that 'increment' adds to current usage and 'set' replaces it, and implies 'increment' is the default. This goes beyond the schema's enum description.

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 tool's purpose: 'Report usage for a metered subscription item.' It specifies the resource (usage record) and verb (create/report), and distinguishes between the two actions 'increment' and 'set'. This differentiates it from sibling tools like ls_get_usage_record or ls_list_usage_records.

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 explicit guidance on when to use each action ('increment' to add, 'set' to replace). While it doesn't explicitly state when not to use this tool, the context of sibling tools and the clear action guidance makes usage mostly clear.

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