Roam2Go eSIM Catalog

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

Annotations already cover read-only, idempotent, and non-destructive behavior, so the description doesn't need to restate those. It adds useful contextual value by disclosing that the response includes the purchase link, which is not evident from the schema or 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?

A single, front-loaded sentence that states the action, target, and key detail about the return value. Every element earns its place and there is no fluff.

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 single-parameter read operation with strong annotations, the description is complete: it tells the agent what action to take, which parameter to provide, and what notable data to expect. The sibling tools help situate it, and no critical invocation information 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?

With 0% schema description coverage, the description compensates by explaining that 'id' is the plan identifier and provides a concrete example ('R2G-7224'), which gives format insight beyond the plain string type. It could further explain how to obtain the ID, but the example is sufficient.

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 uses a specific verb ('Get') with a clear resource ('one plan by its id'), and distinguishes itself from siblings by indicating a singular ID-based lookup rather than listing destinations or searching plans. The example ID format ('R2G-7224') reinforces what is being fetched.

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 phrase 'by its id' clearly implies this tool is for cases where the plan ID is already known, which contrasts with search_plans for finding plans. It does not explicitly name the alternatives or provide when-not-to-use guidance, but the context is unambiguous enough for an agent.

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, so the safety profile is covered. The description adds value by specifying the return format (country name + code + cheapest plan price in EUR), which is useful for an agent to know what to expect, especially since there is no output schema. It doesn't describe edge cases like empty lists, but for a simple read-only listing tool this is sufficient.

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, focused sentence that leads with the action and resource, then clarifies the output contents in a parenthetical. Every word earns its place; there is no redundancy or filler.

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 tool with no output schema, this description tells the agent exactly what it returns and the fields included. It covers all necessary information to call the tool correctly and interpret the result. Nothing essential is missing for the tool's simplicity.

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?

There are zero parameters, and the input schema is empty. The description does not need to explain any parameters, and it correctly avoids repeating anything about the schema. Per the baseline rule for 0 parameters, a score of 4 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 verb ('List') and the resource ('all destinations'), and specifies the exact fields returned (country name, code, cheapest plan price in EUR). This distinguishes it from siblings like get_plan (which likely retrieves a single plan) and search_plans (which searches plans), so an agent can immediately tell when to use it.

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 gives no guidance on when to choose this tool over alternatives. It simply states what it does; it does not mention when to use it (e.g., 'when you need a full list of destinations') or when not to use it, nor does it reference siblings or any prerequisites.

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, and destructiveHint=false, so the description does not need to restate these. However, it adds meaningful behavioral details about the search semantics (destination matching, inclusion of regional plans, pagination behavior) that go beyond the annotations, enhancing transparency without contradiction.

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 well-structured and every sentence adds value. It leads with the primary purpose, then explains matching behavior, examples, and pagination. Though moderately long, the content is dense with essential information and avoids redundancy.

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 search tool with no output schema, the description covers the key aspects: it lists the fields returned (price, data, validity, activation policy, purchase link), explains pagination via 'matches' and 'returned', and specifies the limit maximum. It provides enough context for an agent to understand the tool's behavior and response structure.

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 description significantly enriches the parameter definitions. It elaborates on 'destination' (matching on name, language support, regional coverage) and 'limit' (pagination and max value), providing context that the schema descriptions alone do not convey. This helps the agent use parameters effectively.

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?

Clearly states the tool's core function: searching travel eSIM data plans by destination name. The description is specific about the verb (search), the resource (eSIM plans), and the scope (by destination), making it easy to distinguish from sibling tools like get_plan (which likely fetches a single plan) and list_destinations (which lists available destinations).

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 explicit, actionable guidance on how to use the tool, including matching behavior (country names in any major language, regional/global plans included) and concrete examples (e.g., 'France' also surfaces the Europe plan). It also explains pagination parameters ('matches' and 'returned') and the limit parameter (max 40). While it does not explicitly contrast with siblings, the usage guidance is thorough and leaves little to inference.

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