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

The annotations already establish that this is a safe, idempotent, open-world read. The description then adds genuinely new behavior: whether the yields are live or an hour stale depends on the account, and accounts without a key get a note rather than numbers. That latency and auth context is not available anywhere in the structured fields. It doesn't cover rate limits or the 5-credit cost of the fresh flag, which only the schema mentions.

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?

Two sentences with no filler, and the payload of report contents is front-loaded. The trailing clause 'a note instead of numbers without one' is a slightly opaque way of saying the response degrades to a message when unauthenticated.

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, so the description has to describe what comes back and it does: yields, spreads, regime classification, and the time of the flip. The important remaining gap is how it differs from a sibling such as get_treasury_curve, which the description leaves unaddressed.

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 coverage is 100%, and the single optional 'fresh' parameter is fully documented in the schema, including its cost and its no-effect-without-a-key caveat. The description's reference to 'current or an hour behind according to the connected account' explains why freshness is account-dependent, but it adds no syntax or format detail beyond what the schema provides.

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 concrete resource and contents: Treasury yields, 2s10s and other spreads, and curve regime with the flip time. That is far more specific than the sibling get_curve_history or get_yield_closes names alone. However, it never distinguishes itself from get_treasury_curve, which sounds like it returns much the same thing, so an agent has no basis for choosing between 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 statement of when to use this tool rather than get_treasury_curve, get_yield_closes, get_curve_history, or get_rate_path, and no exclusions or prerequisites are given. Usage has to be inferred entirely from the tool name.

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