Cheapest eSIM Korea (최저가e심)

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

Annotations already declare readOnly=true, idempotent=true, destructive=false, so the safety profile is covered. The description usefully adds what the ranking is computed on (cheapest unlimited plan per identical trip length), but says nothing about result ordering beyond 'cheapest first', pagination, or whether countries without available plans are excluded. The trailing '(화면 규칙)' is opaque.

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-loaded and short in absolute terms, but the Korean sentence largely restates the English one, so roughly half the text is duplication that adds no new information. The parenthetical '(화면 규칙)' adds noise rather than meaning.

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 3-parameter read-only tool with no output schema, the description conveys the core intent, the ordering metric, and the trip-length-locking requirement. Enough to call it correctly, though output shape and the 'form' parameter's effect remain unstated.

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 67%: 'days' and 'limit' have descriptions, but the 'form' enum has none. The description reinforces that 'days' must be constant across the comparison, adding a little meaning beyond the schema, but it never clarifies the esim/usim 'form' choice. Baseline 3 is appropriate given partial coverage.

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 ('ranks destination countries by the cheapest unlimited travel eSIM (or SIM) price') plus the equating condition ('for the same trip length'). An agent can distinguish this ranking/comparison operation from sibling 'find_esim_prices' by the ranking framing, 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?

No when-to-use or when-not-to-use guidance, and no sibling alternatives are mentioned. The 'for the same trip length' clause hints at the comparison scenario, but the agent must infer whether this or find_esim_prices is the right call.

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

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

Annotations already cover safety (readOnly, idempotent, non-destructive, closed-world), so the description earns credit for adding provenance and freshness context: data is 'collected and verified daily' from Naver SmartStore, and pagePrice follows the same rules as the website/app. It still omits auth needs, rate limits, and failure behavior for unknown countries.

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?

Core purpose is front-loaded in the first clause, which is good, but the body is a near-verbatim bilingual duplication (Korean and English say the same thing), effectively doubling length without adding information for the agent.

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 7 parameters, no output schema, and no nested objects, the description does the needed work of explaining the return shape: sellers ranked by reviews or price, cheapest pagePrice, and cheapest daily-cap/total-cap/USIM/adjacent-day alternatives. Missing edge-case behavior (unknown country/city, no results) keeps it short of full completeness.

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%, so the schema already documents every parameter including plan types, day ranges, and the '3박 4일 → days=4' convention. The description largely restates plan types (unlimited/daily/total) and ranking rules already in the enum descriptions, adding little parameter-level meaning beyond the schema baseline.

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+resource with full scope: verified daily eSIM/SIM prices from Naver SmartStore, keyed by destination country or major city (54 countries) and trip length. The single-destination framing plus the explicit 'for a destination country or major city' qualifier implicitly separates it from siblings like compare_countries and get_price_trend.

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 implied rather than stated: the description makes clear this is the per-country/per-duration price lookup, but it never names an alternative or gives a when-not-to-use condition, despite siblings (compare_countries, get_price_trend, get_seller_profile) that clearly overlap in domain.

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

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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description still adds real value beyond that: it discloses that the output is a historical record plus an evaluative judgement, and that no forecasting is performed — a behavioral limit an agent would otherwise assume.

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?

The core purpose is front-loaded in the first clause, and the 'does not forecast' caveat is placed last where it belongs. The bilingual Korean restatement of the same content roughly doubles length without adding new information for an agent, which is a minor cost.

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 read-only, 3-parameter tool with no output schema, the description adequately conveys what comes back (daily history plus judgement). The remaining gap is that 'recent' is never quantified — the observation window length is unspecified — and the form parameter's effect is unaddressed.

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 67%; country and trip length are reflected in the description text, but the 'form' parameter (esim/usim) is never mentioned — and the description's phrasing 'cheapest unlimited eSIM price' arguably implies esim-only, when the schema accepts usim too. The days enum values and default are also left to the schema.

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+resource: returns a daily history of the cheapest unlimited eSIM price for a country and trip length, plus a cheapness judgement. That is clearly distinguishable from siblings like find_esim_prices or compare_countries, though the description never names or contrasts those siblings 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 implied (use it when you want the recent trend / a 'is now cheap?' judgement), and it adds one boundary — 'Does not forecast' — which tells the agent not to expect a prediction. However there is no explicit when-to-use-vs-alternative routing against find_esim_prices or compare_countries.

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

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds genuinely new context — the 30-day history window, the today-vs-30-day scope, and the 'independent comparison service, not affiliated with sellers' disclaimer — but says nothing about unknown-seller behavior or failure modes.

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?

The same content is written twice, once in English and once in Korean, roughly doubling the length with zero new information. It also leads with a laundry list of metrics instead of a front-loaded statement of what the tool is, so the purpose is buried behind output detail.

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 must carry the return-value burden, and it does describe the returned metrics in detail. However, it omits sibling disambiguation and any indication of what happens with an unrecognized seller, which leaves gaps for a tool whose neighbor get_price_trend sounds like a plausible substitute.

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 'seller' parameter already carries an enum-like example list (말톡, 도시락이심, 유심사스토어), so the schema does the heavy lifting. The description never mentions the input parameter at all, adding no meaning beyond the schema; 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 the resource precisely (an eSIM seller's operational profile) and enumerates the specific metrics returned: price-change frequency, sold-out option ratio, cheapest country/day cells, and official-vs-Naver price cross-check. The verb 'get' is implied rather than stated, and it never distinguishes itself from the adjacent sibling get_price_trend, which the 'how often a seller changed prices' metric overlaps with.

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 at all. An agent cannot tell from this text whether to call get_seller_profile, get_price_trend, or find_esim_prices for a given price question, and no prerequisite (e.g., a valid seller name) is mentioned.

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

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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=false and destructiveHint=false, so the safety profile is fully covered by structured data. The description adds the useful facts that the result set is fixed at 54 countries and that it carries precomputed cheapest-price fields, but says nothing about ordering, pagination (none needed at 54 rows) or freshness of the price data.

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?

The content is front-loaded and short in absolute terms, but it is stated twice in English and Korean, with the second sentence largely re-stating the first while re-listing the same field set. That duplication is pure repetition rather than added meaning.

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 parameters and no output schema, the description is the only place the return fields can be documented, and it does document them along with the row count. It is therefore adequate for calling the tool, losing only a little to the redundant bilingual phrasing.

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?

The tool takes zero parameters, so there is nothing for the description to disambiguate and the baseline is 4. The description correctly adds no parameter chatter and instead spends its words on the shape of the returned records.

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 (destination countries covered) and enumerates the fields returned (key, Korean name, seller count, 3-day unlimited eSIM cheapest price), so an agent knows exactly what this list contains. It does not, however, distinguish itself from compare_countries, which also operates on the country set.

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 mention of the sibling tools. An agent must guess whether to call list_countries or compare_countries first; the description only describes content, not the selection condition.

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