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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description usefully adds the tariff basis (2026 KEPCO residential low-voltage table, other season) and that the result is an estimate carrying its source and page URL, but says nothing about how the estimate is computed or what happens with default parameters.

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?

Front-loads the purpose and modes, which is good, but the middle sentence mixes Korean reference text and a website URL that do little for an invoking agent, and the sizing is uneven for the amount of actionable information conveyed.

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 output schema, the description partially covers returns ('an estimate with the source and page URL'), and it grounds the calculation in a named tariff. It stops short of documenting units or the meaning of defaults, but is reasonably complete for a read-only calculator.

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 only 38% across 8 parameters, so the description has to compensate. It clarifies the key mode-dependent semantics (home = progressive tiers using other_kwh, shop = unit_price x kWh), which maps mode/unit_price/other_kwh, but the remaining wattage, count, led_cost and hours parameters get no explanation beyond their names.

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?

States a specific resource (Korea LED replacement savings) and the two calculation modes (household tiers vs shop unit price), which lets an agent distinguish it from the country siblings jp_led_savings, ph_led_savings and tw_led_savings. The verb is implicit (it is a calculator), but the scope is clear.

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?

The description implies two usage paths via the mode parameter and the Korean reference note (household = KEPCO tariff, shop = enter your own unit price), but it never explicitly says when to pick this tool over kr_electricity or the other LED tools. Guidance is inferred rather than stated.

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