Bloomy eSIM

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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds a genuine behavioral detail – the exact computation (activity MB × days × Wi-Fi factor × 1.15 buffer, rounded up) – which explains how results are derived, though it omits units, rounding output format, and what 'daily MB per activity' values are assumed.

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?

A single tightly-packed sentence with no filler, and the formula is front-loaded. The external-site reference is of marginal value to an agent but does not pad the text.

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 tool with no schema descriptions and no output schema, the description should specify input units, the meaning of the wifi enum, and the shape/units of the returned estimate. It leaves all of that implicit, so an agent cannot confidently populate or interpret the call.

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 0% across three parameters, so the description is the only source of meaning. It names 'days' and 'Wi-Fi factor' but never explains the wifi enum values (rarely/sometimes/often), the 1–180 day range, or the activity vocabulary, leaving real gaps.

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 gives a formula rather than stating what the tool produces; a reader must infer from the expression that it estimates mobile data consumption for a trip. The name and title ('estimate_data' / 'Estimate data needed') carry most of the purpose, and no verb+resource statement distinguishes it from get_plan or recommend_plan.

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 guidance on when to use this versus siblings like recommend_plan or get_plan, and no prerequisites or exclusions. The reference to an external calculator implies a comparison use case but never says when an agent should prefer this tool.

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 (readOnlyHint, idempotentHint, non-destructive, openWorldHint false). The description adds useful detail about returned content (data, validity, network, 5G, top-up, carriers, price, checkout link), but it discloses nothing about authentication, rate limits, errors, or other behavioral traits beyond the annotations.

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 description is a single front-loaded sentence that lists the returned fields with no filler. Every item is relevant to a get-one-plan operation.

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 simple read-only tool with rich annotations and no output schema, the description usefully enumerates returned fields. However, it leaves plan_id unexplained and does not describe response structure; the schema covers the other parameters, so the remaining gaps are moderate.

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 schema describes days and lang thoroughly, including lang's purchase-page effect and default. plan_id is undocumented in both schema and description. The description mentions only 'one plan' and adds no parameter syntax, constraints, or meaning, so it does not compensate for the 67% schema description coverage 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?

The description identifies a specific verb (details) and resource (one plan) and enumerates returned fields such as data, validity, network, and price. It is clear for a fetch-by-id tool, but it does not distinguish this from siblings like get_purchase_link, which likely also returns a checkout link, or search_plans.

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 provides no when-to-use guidance, no conditions for choosing this tool over alternatives such as search_plans or recommend_plan, and no prerequisites or exclusions. It only describes what the tool returns.

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 and non-destructive behavior, so the safety profile is covered. The description goes further by stating the tool never takes payment, that the traveler pays at the confirmation screen, and that the QR code arrives by email and in My Page after payment — meaningful behavioral context beyond the structured fields.

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 what the tool returns, then the payment and post-payment behavior. Every sentence carries information. The opening phrase 'Link straight to the final confirmation screen' is slightly clipped but 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?

There is no output schema, so the description must convey what the agent gets back; it describes the link, the payment boundary, and the QR code delivery. With read-only/idempotent annotations covering safety, this is close to complete, though it never describes the link's format or expiry.

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%: lang and days are well documented in the schema, but the required plan_id has no description. The description references 'this plan' but adds no parameter-level detail (e.g., format of plan_id, when days is needed), so it neither compensates for the gap nor abuses the reader. 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 clearly states the resource: a link to the final confirmation/checkout screen for a specific plan. The implied verb (return a purchase link) is unambiguous and distinguishable from siblings like get_plan or estimate_data. It stops short of explicitly naming an alternative, but the purpose is immediately graspable.

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?

It conveys that the traveler pays at the destination and that no payment is taken here, which implies a pre-purchase context. However, there is no explicit when-to-use guidance, no prerequisites, and no reference to the sibling tools (get_plan, estimate_data, recommend_plan) that an agent would need to route between.

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, openWorldHint=false and destructiveHint=false, so the safety profile is covered. The description adds useful content-scope context (what topics the guide covers, that it links out to a device checker and troubleshooting), but says nothing about auth requirements, return format, or that the response is static reference content.

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?

A single compact sentence with the substantive content front-loaded; every clause adds information. It is a noun phrase rather than a full sentence, which slightly weakens readability but not content efficiency.

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 reference tool with no output schema, the description does the important work of previewing what the guide contains and that it links to further resources. Annotations cover the safety profile and the schema covers lang; the only residual gap is the undocumented device semantics.

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 50%: lang is richly documented in the schema (default en, price fields unaffected by language), but device has an enum with no description. The description's '(iPhone or Android)' partially compensates for device, yet it says nothing about the lang parameter, so it does not fully close the coverage 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?

States a specific verb+resource (get setup guide) and enumerates the content returned: setup steps for iPhone/Android, pre-purchase checks, and links to the full guide, device checker and troubleshooting. It is clearly an informational tool, distinguishable from the plan/destination/purchase siblings, though it never names an alternative 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 only implied by the content list – an agent can infer this is for setup and pre-purchase guidance, but there is no explicit when-to-use statement, no trigger conditions, and no mention of the sibling tools it complements (e.g. get_purchase_link).

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 safety is fully covered. The description adds that results are filtered by query and include lowest price, but doesn't disclose pagination, result size, or output ordering. With annotations carrying the safety profile, this is modest added 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 tight sentences: returned fields first, filtering behavior second. Every clause carries information; nothing is padded.

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-required-param read-only listing tool with fully documented schema, the description covers what it returns and how to filter. It stops short of output shape details (field types, whether results are paginated), which would be useful but are not strictly required. No output schema exists, so some return-shape explanation would have helped.

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%, and the schema already explains lang's default and that language never affects plan or price, and that query matches part of a name or code. The description's 'Filterable with query' merely restates what the schema says, adding no syntax or matching-behavior detail beyond it.

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 resource (countries with a plan) and enumerates returned fields (ISO code, localized name, plan count, lowest price), so the agent knows exactly what it yields. It is clearly a discovery/enumeration tool distinguishable from siblings like search_plans or get_plan, though the description doesn't explicitly name those alternatives.

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?

Says it is filterable with query, which implies a use case, but gives no explicit when-to-use vs alternatives guidance. An agent must infer that this is the entry point for discovering which countries have plans before calling get_plan or estimate_data.

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 genuine behavioral value beyond them: it defines the three recommendation tiers (best_fit = cheapest covering the estimate, budget = below estimate, roomier = next size up) and states that each option carries a direct link to checkout confirmation. It does not mention auth, rate limits, or what happens when no destination is supplied.

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?

Four sentences, front-loaded with what the tool does and what it returns, with the input conditions appended. The final sentence about destinations partially repeats schema content already covered, but nothing is padded or circular.

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 takes on the burden of explaining returns and does so concretely (three tiers, their definitions, and the checkout link). It also explains the multi-country input pattern and the optional data-usage input. Only the behavior when neither destination nor destinations is supplied is left unstated, a minor gap against otherwise complete 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 100%, so every parameter is already documented in the schema, including the destination/destinations alternative and the usage/activities/min_gb override chain. The description restates the multi-country destination pattern and the total-days convention but adds no format or defaulting detail beyond what the schema provides, which is the baseline-3 case.

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 verb and resource (recommend a data plan from destination + trip length) and goes further by describing the exact shape of the result: up to 3 named options (best_fit, budget, roomier) with a reason and a checkout link each. That output profile is distinctive enough to separate it from search_plans and estimate_data, which do not return curated, purchase-ready recommendations.

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?

It gives clear context for use: supply destination (or every country of a multi-country trip in destinations), trip length, and data usage 'if known', implying the tool works with partial input. It never names an alternative or an exclusion (e.g. when to use estimate_data instead), so it stops short of full routing guidance.

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=false, and openWorldHint=false, so the safety profile is covered. The description adds genuinely useful behavior beyond that: a deterministic ordering (cheapest first, then single-country before multi-country), which materially affects how an agent reads the returned list.

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, no filler. The most decision-relevant fact (what it lists and the ordering) is front-loaded, and the filter summary follows.

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 search tool with full schema descriptions and no output schema, the description covers selection and ordering, which is most of what an agent needs. It is only slightly thin on the shape of a returned 'plan' and how limit interacts with the result set, but those are minor given the rich parameter descriptions.

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 every parameter (lang, limit, min_gb, min_days, plan_type, destination) is already documented in the schema, including enum meanings and defaults. The description only names three filters already fully covered there, adding no syntax, units, or edge-case detail 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 a specific verb and resource ('List plans for a destination') and even specifies the result ordering (cheapest first, single-country before multi-country). It is clear what the tool returns, but it never differentiates itself from siblings like recommend_plan or get_plan, which an agent could plausibly confuse with a plan-listing/search tool.

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 only guidance is 'Filter by trip length, minimum GB, and plan type,' which restates filter parameters rather than saying when to choose this tool over recommend_plan or estimate_data. There is no when-not guidance and no mention of prerequisites or follow-up tools (get_plan, get_purchase_link).

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