compare_tickers

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

Annotations already declare readOnly/destructive/openWorld, and the description adds substantive context beyond them: no account access, no order placement, no FX conversion, warning surfaces (stale spread over 5 minutes, missing options/SEC/consensus data on KRX), and error semantics (ok=false names the problem). The non-idempotent annotation is consistent with a live-quote-dependent comparison.

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?

Purpose and the alternative-tool routing are front-loaded, and nearly every clause carries operational information with no filler. However, the body is delivered as a few very long run-on sentences packing currency policy, KRX rules, return shape and detail levels together, which makes it harder to scan than it needs to be.

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, multi-market comparison tool this is unusually complete: symbol formats, currency policy, partial-failure behavior, freshness, detail levels and error envelope are all addressed, and an output schema exists so return values need little further explanation. The only omission is horizon_days, which is minor against the overall coverage.

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 only 17%, so the description carries most of the burden and does so for symbols (format, exchange suffix fallback .KS/.KQ, mixing rules), currency (defaults to listing currency, mismatch behavior, required with total_amount when mixed), total_amount (percentage-only plan for cross-currency tickers), and confirmed_only (confirmed closes). horizon_days is never explained anywhere, and detail is largely covered by the schema itself rather than the description.

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 verb and resource with scope (1–8 tickers, entry-plan scoring and allocation) and immediately disambiguates from siblings by naming compare_price_performance for charts/relative strength. It also clarifies it is a calculation, not an order, so the agent knows what class of operation this is.

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?

Explicitly routes between tools ('For price-performance charts or relative strength (상대강도), use compare_price_performance') and states what is out of scope (indices, other markets). It also gives the conditions that select behaviors: mixing US and KRX tickers, CURRENCY_MISMATCH when currency conflicts, and unsupported symbols landing in data.unavailable rather than failing the whole call.

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