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

With no annotations, the description carries the full burden. It lists the included data elements but does not disclose data frequency, historical depth, or the methodology behind the recession probability. The mention of 'inversion signals' hints at derived metrics but does not explain their calculation or behavior.

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 a single sentence that front-loads the core topic ('US Treasury yield curve') and then lists outputs in a compact, structured way. No unnecessary words or repetition—every phrase adds value.

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 the tool's low complexity (0 params, no output schema), the description covers the primary outputs effectively. However, it omits whether the data is historical or current, and it does not differentiate from yield_curve_v2/v3, leaving minor gaps for an agent in a broader context.

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 has zero parameters, so the schema is vacuous. The description adds meaning by clarifying what the tool returns (yield curve data, spread, signals, probability), which is essential when there are no parameters. Per calibration baseline, 0 params warrants a 4.

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 clearly identifies the resource (US Treasury yield curve) and enumerates specific outputs: all maturities, 10Y-2Y spread, inversion signals, and recession probability. This level of detail distinguishes it from sibling tools like yield_curve_v2 and other economic indicators, making the tool's purpose unambiguous.

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?

No guidance is provided on when to use this tool versus alternatives such as yield_curve_v2 or other dashboards. The description lacks any exclusions, prerequisites, or context about selection, leaving the agent without direction on tool choice.

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