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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=true), so the bar is lower, but the description adds only one behavioral detail — that each series carries its own observation date. With no output schema, there is no disclosure of units, staleness, holiday behavior, or response shape.

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?

One front-loaded sentence with no filler; the long series list is the highest-value content because it defines coverage, and the trailing 'each with its observation date' delivers a key caveat in a single clause.

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 with no output schema, listing every returned series plus the observation-date caveat is nearly enough. It falls short only on units (percent vs. basis points), update frequency, and what happens on non-business days or future dates.

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% and the single 'date' parameter already documents 'YYYY-MM-DD, default today'. The phrase 'on a date' in the description adds nothing beyond the schema, so the baseline 3 applies.

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 states a specific resource (official Korean interest rates on a date) and enumerates the exact series returned — BoK base rate, call, KOFR, CD, CP, MSB, KTB 1y-50y and spreads. That enumeration clearly separates it from siblings like kr_fx, though no sibling is named explicitly.

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?

Usage is only implied: the enumeration of a full rate curve signals this is the tool for Korean won interest rates rather than FX or other data, but the description never says when to prefer it over kr_fx or how to interpret a partial curve. No exclusions or prerequisites are given.

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