get_buying_power

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

Annotations already declare readOnlyHint, idempotentHint, and openWorldHint, so the safety profile is covered. The description adds genuine behavioral context beyond that: the returned figure excludes 미수 (unsettled) funds, and no FX conversion happens, so USD buying power is a distinct balance rather than a converted KRW value.

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 short sentences with the core purpose front-loaded and no filler; the secondary note about USD is placed immediately after the main definition. Minor waste from the trailing blank line, but otherwise 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?

For a two-parameter read tool with full schema coverage but no output schema, the description omits what the response actually looks like (amount field, currency unit, behavior when the account has no balance). It is adequate to call correctly but leaves return-value and sibling-selection questions unanswered.

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%, with the currency enum and the account_seq default fallback (TOSSINVEST_ACCOUNT_SEQ) both documented in the schema. The description reinforces the currency split by explaining why USD is separate, but adds no format, unit, or edge-case detail beyond that, so the baseline 3 is appropriate.

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 names a specific verb and resource (조회한다 / buying power) and qualifies the scope precisely as cash-based with no unsettled (미수) amount included. It does not, however, distinguish itself from nearby siblings such as get_sellable_quantity or get_holdings, which an agent may consider for similar questions.

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 second sentence gives implied usage guidance: because US orders have no auto currency conversion, the USD balance must be queried separately, which tells the agent it may need two calls. There is no explicit statement of when to use this tool instead of get_sellable_quantity or get_holdings, and no prerequisites or exclusions.

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