openclaw_usage_cost

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

With no annotations provided, the description must carry the burden of behavioral disclosure. It declares the tool as 'Read-only,' which is critical, and indicates it wraps an internal API (`usage.cost`). However, it omits details like error handling, pagination, response format, or rate limits, which are important for safe invocation.

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 extremely concise with two sentences, each adding value. The main action is front-loaded ('Get usage cost breakdown'), followed by clarifying details. No fluff or repetition.

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 absence of an output schema and low schema coverage, the description provides a high-level overview but lacks detail about the returned data structure, how filters combine, or what 'cost breakdown' entails. For a tool with 4 parameters and no explicit output specification, more completeness would be beneficial.

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 only 25% (only 'instance' documented). The description compensates by clarifying that 'agentId', 'sinceMs', and 'untilMs' serve as agent and period filters, adding semantics beyond the raw schema. It does not fully detail parameter interactions or constraints, but significantly improves understanding.

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 retrieves a usage cost breakdown, specifying dimensions (per agent, per model, per period). It uses a specific verb ('Get') and resource ('usage cost breakdown'), and distinguishes from siblings like openclaw_usage_status by focusing on costs. The mention of wrapping `usage.cost` adds transparency.

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 basic guidance on passing period and agent filters, but does not explicitly specify when to use this tool over alternatives (e.g., openclaw_usage_status) or when not to use it. The phrase 'if supported' implies conditional behavior but lacks full context.

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