cursor_usage

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

No annotations are provided, so the description carries the full burden. It discloses the notable behavioral trait that the underlying activity 'costs real money', framing this as a cost-auditing read, but never states read-only safety, auth needs, rate limits, or whether the result is cached/live.

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 short sentences, front-loaded with the resource and followed by the motivational cue. Every clause carries information; only the slightly informal tone keeps it from a 5.

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 two-parameter read tool with no output schema, the description covers what is returned (token usage and cost) but not the shape of the return, units, or how cost is attributed across runs. Adequate but with clear gaps for a cost-reporting 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?

Schema coverage is 0% and neither parameter is described in the schema, but the phrase 'an agent (or one run)' maps agent_id to the broad scope and run_id to the narrow one-run scope, adding genuine meaning. It does not explain accepted ID formats or the empty-string default on run_id.

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?

States a specific resource (token usage and cost) and scope (an agent, or one run), which is clearly distinct from siblings like cursor_status or cursor_result. It lacks an explicit verb (e.g., 'retrieve'), but the intent is unambiguous.

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?

Gives one usage cue ('check this when a run felt expensive'), which is a real trigger condition but no explicit alternatives or when-not guidance. An agent can infer usage but is not routed against sibling cost/status tools.

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