report_step_cost

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

Since no annotations are provided, the description carries the burden of behavioral disclosure. It does disclose the accumulation and flushing behavior, which is key context. However, it does not mention whether this is a mutation operation, any side effects, authentication requirements, or what happens on success/failure. The provided behavior is useful but incomplete for a write tool with no annotation coverage.

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 exactly two sentences. The first sentence states the purpose directly, and the second provides critical behavioral context about accumulation and flushing. Every word is necessary, with no filler or redundancy.

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?

The description covers the essential behavioral context (accumulation and flushing) that is not evident from the schema. However, for a tool with 7 parameters, no annotations, and no output schema, it lacks details about parameter usage, required fields, and what happens during execution. It is not completely inadequate but leaves significant gaps in how to invoke the tool correctly.

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?

The schema has 7 parameters with 0% description coverage. The description does not mention any parameter names, meanings, or constraints beyond the generic phrase 'cost of a completed pipeline step.' It fails to explain required parameters (step_name) or the token fields, leaving the agent to infer from names alone. The description adds no value to parameter semantics.

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 specific action: 'Record the cost of a completed pipeline step.' This uses a precise verb ('Record') and identifies the resource ('cost of a completed pipeline step'). It also distinguishes itself from siblings by focusing on per-step cost recording, whereas siblings like estimate_cost and report_session serve different purposes.

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 explains that costs accumulate per step and are flushed when report_session is called, implying this tool is for incremental recording before a final session report. This provides clear context for when to use it, though it does not explicitly name alternatives or state when not to use it. The sibling tools (estimate_cost, report_session) are implicitly differentiated by this behavior.

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