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 the safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower. The description adds genuinely useful behavioral context beyond that: prices are collected and verified daily, ranking is by review count, and pagePrice follows the same rule as the website/app.

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 and ranking/pricing behavior are front-loaded, which is good. The Korean sentence largely restates the English content, making roughly half the description redundant from a structural standpoint, though it may serve bilingual users.

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 carries the return-shape burden and does so adequately: it explains that sellers are ranked by reviews and that the cheapest price (pagePrice) is returned. Country examples and default types round it out; only explicit sibling routing is missing.

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 100%, so the baseline is 3. The description earns above baseline by clarifying that 'daily' means N GB/day and 'total' means N GB total, explaining how the type and gb parameters interact, and confirming the 1-30 day trip-length bound.

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+scope: it returns verified daily eSIM/physical SIM prices for a destination country and trip length, ranked by reviews. An agent can clearly tell it apart from trend/comparison/profile siblings by the resource. It stops short of naming which sibling to prefer, so 4 rather than 5.

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 sets context (Korean travelers, Naver SmartStore, 1-30 day trips) and lists the default plan types, implying when the tool applies. However, it never states when NOT to use it or names the alternatives (compare_countries, get_price_trend, get_seller_profile, list_countries), leaving routing to inference.

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 the safety profile (readOnly, idempotent, non-destructive, closed-world). The description adds value beyond them: it discloses that the result includes both the daily series and a comparative 'is it cheap now' judgement, and explicitly states the tool does not forecast prices.

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, front-loaded with the core resource before the constraints. Deducted one point because the Korean text is a full restatement of the English rather than additive information, doubling the length for no new semantics.

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 does describe the return shape (daily history plus judgement), which is a real contribution. However, for a 3-parameter tool at 33% schema coverage, the unexplained 'form' parameter and the ambiguous trip-length enum are left for the agent to guess.

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 33%: 'days' carries a bare default note and 'form'/'country' have no schema descriptions. The description loosely maps 'country' and 'trip length' (days) to the inputs but never explains the trip-length enumeration or what 'form' (esim vs usim) selects, so it only partially compensates for the gap.

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?

Names a specific resource and scope: 'Daily history of the cheapest unlimited eSIM price for a country and trip length, with a judgement of whether today is cheap'. This clearly separates it from the cross-country compare_countries and the current-price find_esim_prices by scope, 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?

There is no statement of when to pick this over find_esim_prices or compare_countries. The one piece of guidance is a negative scope boundary ('Does not forecast'), which usefully blocks misuse for prediction but leaves the positive use case to inference.

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/idempotentHint/destructiveHint/openWorldHint, so the safety profile is covered. The description adds one genuinely useful non-schema fact — that the service is independent of the sellers it reports on — but says nothing about behavior on an unknown seller name, return shape, or data freshness.

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 deliverable list is front-loaded and each metric earns its place, but the entire content is written twice (English then Korean), roughly doubling length for identical information. The affiliate disclaimer is also repeated verbatim in both languages.

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 does the work of outlining what comes back — three named metric groups tied to the seller — which is enough for an agent to decide and call. It stops short of describing units, cell format, or empty-result behavior.

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?

Only one parameter (seller) at 100% schema description coverage, including Korean example values, so the schema carries the semantics. The description adds no extra meaning about the seller identifier (e.g., exact-match vs alias, case sensitivity).

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 the concrete outputs for a seller: price-change frequency (increases/decreases), sold-out option ratio, and the country/day cells where it is cheapest. An agent can tell this is a seller-level metric lookup, though it never states the verb ('return/get') nor distinguishes itself from the sibling get_price_trend, which overlaps on price-change data.

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 guidance is given: no condition that selects this over get_price_trend (price changes), find_esim_prices (current prices), or compare_countries. The only routing-adjacent sentence is the affiliation disclaimer, which is about trust, not tool selection.

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, idempotentHint, and destructiveHint=false, so safety is covered. The description adds value by disclosing the shape of each returned record (key, Korean name, seller count), which matters because there is no output schema. It does not mention ordering or result size, which is a minor gap.

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 content front-loaded. The Korean sentence largely restates the English rather than adding information, which is mild redundancy, but it is plausibly intentional for a bilingual audience and costs little.

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 zero-parameter, read-only lookup tool with full annotation coverage, the description supplies the one thing structured data cannot: what each entry contains. No output schema exists, and the field list compensates adequately. Ordering/pagination details would be the only remaining nicety.

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 the baseline of 4 applies. The description's field listing describes return values rather than inputs, which is appropriate here and adds no confusion.

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 clear verb (list) and resource (destination countries covered) and even enumerates the returned fields (key, Korean name, seller count). It implicitly distinguishes itself from compare_countries by being the enumeration source rather than a comparison tool, but never names that relationship 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 guidance is given. With siblings like compare_countries and find_esim_prices that likely consume country keys, the description should say this is the tool to call first to discover valid keys, but it offers no routing or exclusions.

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