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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=false), so the bar is lower. The description still adds genuine value: it discloses the exact pricing model used (Taipower residential progressive pricing, non-summer, monthly brackets), the upstream code source, and that the result includes a source and page URL — meaningful context for trusting the output.

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?

Three short sentences, front-loaded with scope and model, with no filler. The only waste is the first sentence duplicating the title verbatim instead of stating the action.

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 6-parameter calculator with no output schema, the description covers the model, the provenance, and the return shape reasonably well. It leaves gaps on parameter behavior — what defaults do, whether led_cost drives a payback figure, and how the monthly bracket interacts with other_kwh — which an agent cannot resolve from the schema alone.

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 83%, so the schema already documents nearly every parameter and the baseline is 3. The description adds no parameter-level meaning (no explanation of defaults, of what led_cost=0 implies, or of how other_kwh interacts with the bracket calculation).

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 identifies a specific computation (Taiwan LED replacement savings) with a named tariff basis (Taipower non-summer, monthly brackets) and states it returns an estimate. The region scope implicitly separates it from jp_led_savings/kr_led_savings/ph_led_savings, but no sibling is named and the opening sentence is a verbatim restatement of the title rather than a verb-led statement.

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 when-to-use guidance and no routing to alternatives such as tw_electricity or the other regional LED savings tools. The tariff assumption is stated, which helps a knowledgeable agent judge applicability, but nothing tells the agent when this tool is the right choice versus a sibling.

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