budget_estimate

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

With no annotations, the description carries the burden of behavioral disclosure. It does convey a key safety trait: this tool estimates before spending and does not actually spend. However, it does not disclose whether the estimate is approximate, what the return value looks like, or any side effects or prerequisites.

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 with no filler; the core purpose is front-loaded and the special-case parameter note earns its place. This is appropriately concise for the information it conveys.

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 no annotations, no output schema, and 0% parameter coverage, the description is not complete enough for reliable invocation. It lacks per-kind parameter requirements, units for amount, and any indication of the shape or meaning of the estimate result.

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 0%, so the description must compensate. It only explains that for rag_index, textLength/byteLength can be used instead of amount. It never defines amount, byteLength, textLength, or the meanings of kvp_ops, storage_bytes, and rag_query, leaving critical invocation details undocumented.

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 uses a specific verb ('Estimate') and a specific resource ('whether an operation would hit 402/429 before spending'), making the tool's job unambiguous. This clearly distinguishes it from sibling tools like usage_get, budget_get, and billing_machine_pay, which handle actual usage, budgets, or payments rather than preflight estimation.

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 phrase 'before spending' conveys the general timing and intent of the tool, and the rag_index note gives one concrete usage condition. However, it does not explicitly say when to prefer this over sibling tools or when not to use it, leaving that inference to the agent.

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