estimate_llm_cost

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

With no annotations provided, the description carries the behavioral disclosure burden. It discloses that results are returned for every model, sorted cheapest first, and that numbers are subject to moving caveats like 'batch discounts, prompt caching, intro pricing that expires', signaling estimates rather than exact quotes.

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?

A single sentence packs in the tool's purpose, required inputs, output structure, ordering, and important caveats with no filler. The opening phrase 'Price a workload' immediately establishes the action and target.

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?

Even without an output schema, the description explains what the caller gets: per-request and per-month costs for every model, sorted cheapest first, plus the caveats affecting the estimate. Required inputs are fully documented in the schema, and the optional filter is also described, so the agent has enough information to call 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 input schema already provides 100% description coverage for all four parameters, so the description does not need to re-explain them. It lightly reinforces that tokens are per request and volume is monthly, but adds no meaning beyond what the schema already contains.

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 action ('Price a workload') with a clear resource (cost estimation across 'current frontier and open-weights models'). It also states the return shape: cost per request and per month, cheapest first, which leaves no ambiguity about what the tool does.

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?

It tells the caller exactly what inputs are needed ('tokens per request and monthly request volume') and what the tool produces, making the intended use case clear. It does not explicitly state when not to use it, but the sibling tools are unrelated, so no alternative-based exclusion is necessary.

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