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

Goes well beyond the readOnly/openWorld annotations by disclosing the paid-call model: $0.002 USDC per successful call via x402 on Base, Solana or Arc, with failed calls free. That is decision-relevant cost information no annotation carries. It omits publication lag or refresh cadence, which matter for a monthly index.

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?

Three sentences, front-loaded with what the index is before the disambiguation and the pricing. Every clause carries information, though the payment detail is somewhat dense and could be trimmed without loss.

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 one-parameter read tool with an output schema, the description covers the essentials an agent cannot get from structured fields: data source, series ID, unit type, misleading-name warning, and cost. Nothing needed to call it correctly is missing.

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 100% — the single 'months' parameter already documents its 1–24 range and default of 3. The description adds nothing about the parameter, so the baseline 3 applies.

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 the exact resource and provenance: a US producer price index for lumber and wood products, BLS series WPU081, retrieved via FRED, reported as a monthly index value. It also explicitly disambiguates from the CME Random Length futures contract that the tool name falsely suggests.

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 negative guidance is strong: 'This is a price index, not CME Random Length framing lumber futures or spot quotes' tells the agent when this tool is the wrong choice. It stops short of naming the positive alternative among siblings (e.g. energy_pulp_paper_risi_index or the CME agri futures tool) for agents who do want a traded price.

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