roamflat eSIM Catalog

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

Annotations already declare readOnlyHint=true, openWorldHint=true and destructiveHint=false, so the safety profile is covered. The description adds that the payload is broad (coverage country list, reviews, description, link), hinting at a heavy response, but much of that enumeration duplicates the existing output schema and it says nothing about rate limits or failure modes for an unknown product id.

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 front-loaded sentence naming the tool's identity and scope first, then the payload contents. No filler or repetition, and the key constraint (one plan, by product id) leads the sentence.

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 annotations covering safety, a 100%-covered schema and an output schema that defines the return shape, the description only needs to establish identity and scope, which it does. The remaining gap is the absence of explicit sequencing guidance relative to search_esim_plans and start_checkout.

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 both parameters are already documented, including that product_id originates from search_esim_plans and that language localizes names/labels and the link's currency. The description adds no syntax or format detail beyond that, so the 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?

States a specific verb and resource ('Full details for one roamflat plan') and scopes it uniquely ('by product id'), which cleanly separates it from the search_esim_plans sibling that returns a list. The enumeration of plan attributes reinforces exactly what kind of detail is delivered.

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: the description mentions 'by product id', and the schema notes the id comes from search_esim_plans, so an agent can infer this is the drill-down step after searching. There is no explicit when-to-use, prerequisite, or exclusion statement (e.g. that start_checkout is the next step once a plan is chosen).

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?

The annotations already declare readOnlyHint=true, openWorldHint=true and destructiveHint=false, so the safety profile is covered. The description adds the shape of the result set (best-value plans with specs, prices, link), which is useful, but says nothing about result counts, pagination, ranking logic, or 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?

Three short sentences, front-loaded with the core action and scope, then the return content, then the usage cue. No filler, though it is not maximally dense.

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, open-world search tool with a full output schema and 100% parameter documentation, the description supplies the essential action, scope, return nature, and trigger. Minor gaps around result ordering or limits remain but are not critical.

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 enum plan types, currency override, language localization, and any-language destination handling are already documented in the schema. The description only restates that destination is a country or region, adding no syntax or default beyond what the schema provides.

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 (Find) and resource (roamflat travel eSIM plans) scoped to a destination, and even names what is returned (best-value plans with specifications, prices, and a direct link). It does not explicitly distinguish itself from the sibling get_plan_details, so it stops short of a 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?

Provides a clear usage context: 'Use when a user wants mobile data abroad.' It does not, however, state when to prefer the sibling tools (get_plan_details for a single plan, start_checkout to purchase) or any exclusions, so it falls short of explicit when/when-not routing.

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?

Despite the readOnlyHint=true annotation, the description clearly explains the behavioral nature: it hands off to an external shop, returns buy_url, no account is needed, the eSIM is emailed after payment. This adds substantial context beyond what the annotations provide, covering the interaction model and post-payment fulfillment.

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 three sentences, front-loaded with the core action, and each sentence adds distinct value: handoff behavior, return values, and explicit exclusions. Zero waste.

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?

Complete for this tool. It covers what the tool does, what it returns, prerequisites (no account needed), fulfillment (email), and limitations. With an output schema also present, no critical information is missing for an agent to call it correctly.

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 both parameters (language and product_id). The description does not add syntax or format details for the parameters, so 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?

States a specific verb (hand off to shop), resource (roamflat shop checkout), and scope (buy one plan). This is clearly distinguishable from sibling tools get_plan_details and search_esim_plans, which are for browsing/retrieval rather than initiating a purchase.

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 implies usage context (you use this to complete a purchase after selecting a plan) and explicitly rules out adjacent capabilities, stating there is no in-chat order tracking and no discount-code field. However, it doesn't explicitly name alternatives or state when not to use this tool versus browsing tools.

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