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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false. The description adds valuable context beyond these: 'Source: TreasuryDirect TA_WS, US Government open data, no auth required.' This clarifies access requirements and provenance. It does not contradict any annotation and supplements the safety profile with source attribution.

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 tight: three sentences that state what it does, enumerate return fields, and give use cases plus source. The core purpose is front-loaded, and every sentence contributes. No filler or redundant repetition of the tool name.

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 single-parameter read-only tool with an output schema, the description covers purpose, key fields, use cases, source, and auth. It does not explicitly differentiate from the similar treasurydirect.auction.results sibling, which could lead to mis-selection. However, the output schema and annotations carry most structural details, making this sufficiently complete for an agent to call 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 only parameter 'days' is fully documented in the schema (description, default, min, max, and what it controls). The description merely references 'specified look-back window' without adding new semantics. With schema_description_coverage at 100%, the baseline of 3 is appropriate; there's no additional value to provide.

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 opens with 'US Treasury Inflation-Protected Securities (TIPS) auction results with reference CPI data' — a specific verb-resource pair. It explicitly names the return fields (highYield, interestRate, reference CPI, index ratio, bid-to-cover, total accepted) which distinguishes it from generic treasury auction tools like treasurydirect.auction.results. The title reinforces the TIPS specificity.

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 clear context: 'Useful for tracking real interest rate trends and inflation breakeven calculations.' This tells an agent when to reach for this tool. However, it does not explicitly mention alternatives or state when not to use it relative to sibling tools like treasurydirect.auction.results or abs.economy.cpi. The guidance is implied rather than explicitly comparative.

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