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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior, so the safety profile is covered. The description adds useful content context (daily freshness, spread and inversion coverage) and a 'not investment advice' disclaimer, but says nothing about rate limits, caching, or data provenance.

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 dense sentence with the resource front-loaded and every clause carrying distinct data content. No filler, no repetition of the title.

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?

With no parameters, full annotation coverage, and an output schema present, the description's job is mainly to frame the data. It does that well by listing the fields, though the enumerated return contents partially duplicate the output schema and omit any note on data source or update cadence.

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 tool takes zero parameters, which is the baseline-4 case. There are no parameter semantics for the description to clarify, and nothing misleading is stated.

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 names a specific resource (U.S. Treasury yield curve) and enumerates its contents — daily yields from 1M to 30Y, 10Y-2Y and 10Y-3M spreads, inversion flags. This is clearly distinct from siblings like get_exchange_rates or get_oil_prices, though it never explicitly contrasts itself with them.

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?

There is no explicit when-to-use statement or exclusion of alternatives, but the tool is a zero-parameter single-purpose data fetch, so the usage context (retrieve current Treasury curve data) is strongly implied. No routing guidance between this and other macro/rate tools is offered.

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