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

Annotations already declare read-only, open-world, idempotent, and non-destructive behavior, so the safety profile is covered. The description adds useful result context: no-rate mode returns the latest of each rate, while with-rate mode returns N days including percentiles, volume, and the EFFR target range.

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 compact single sentence that front-loads the resource and conditional behavior, with no filler. The dense acronym list and semicolon clause make it slightly harder to parse, but it remains efficient.

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?

There is no output schema, but the description sketches returned content in both query modes and lists all rate options. With rich annotations and complete schema coverage, an agent has enough to call it correctly, though exact response structure and sibling routing are left unstated.

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%, so both parameters are already fully documented. The description mostly restates those schema semantics and adds return-content context rather than new parameter meaning.

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?

Names the New York Fed reference rates and enumerates all covered rate types, making the resource scope clear. It lacks an explicit verb in the description and does not distinguish itself from the sibling get_treasury_yields, so it stops short of full sibling differentiation.

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?

Provides conditional usage for the rate parameter: omit rate for the latest of each, include a rate for its last N days. It never states when to choose this tool over get_treasury_yields or other financial-data siblings, so tool-selection guidance is only implied.

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