ALT eSIM

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

With no annotations, the description carries the full burden of behavioral disclosure. It does well: states the agent never handles card details (security), the buyer opens the payment URL, the QR is emailed, and charges are in USD. It does not disclose potential side effects like charge failures or rate limits, but covers the key behaviors an agent needs to know.

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?

Every sentence in the description earns its place. It starts with the core action, explains return values, gives the follow-up step, and notes the mandatory email. No redundant or filler content. The structure is logical and flows well.

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?

The description is complete for a tool with no output schema: it explains return values, the post-payment flow, the email requirement, and the currency. It doesn't mention error handling or how to obtain the sku, but those are covered by sibling tools and the schema. Given the tool's complexity, this is adequate.

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 schema already documents all parameters. The description adds some usage context (e.g., stressing the email must be real, mentioning currency), but it does not introduce new semantic meaning beyond the schema. The baseline of 3 is appropriate since the schema does the heavy lifting.

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 tool's purpose: 'Create a secure Stripe payment link for an Alt eSIM plan.' It specifies the resource (eSIM plan), the action (create payment link), and the return values (payment URL and checkout_session_id). It also distinguishes itself from siblings by describing the follow-up with get_qr_code, which is a unique workflow.

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 clear when-to-use context: it's for creating a payment link when a buyer wants to purchase a plan. It gives a sequenced instruction ('After the buyer pays, call get_qr_code') and a mandatory requirement ('You MUST collect the buyer's real email'). It does not explicitly list alternatives or when-not-to-use, but the flow is clear 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?

No annotations are provided, so the description must disclose all behavioral traits. It states it returns 'full details' including specific fields, which is helpful. However, it does not mention if the operation is read-only, any authorization requirements, error conditions (e.g., invalid sku), or rate limits. The description is adequate but could be more transparent about side effects or limitations.

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 extremely concise—two sentences that front-load the purpose and then list returned details. Every sentence earns its place with 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?

Given a simple single-parameter tool, the description covers the purpose, the parameter usage (implicitly), and the return content. It does not have an output schema, so the description compensates by listing returned fields. However, it could be more complete by noting if the tool is read-only or what happens when the plan is not found, but the low complexity keeps this from being a major gap.

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 the single parameter 'sku_or_id' with its type and example. The description does not add further meaning to the parameter beyond what the schema provides, so a baseline of 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 verb 'Get' and the resource 'one Alt eSIM plan by its sku or id', and distinguishes it from sibling tools like 'search_esim_plans' (which lists/filters plans) by specifying a single plan lookup. It also lists the returned fields, adding precision.

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 this tool is for fetching a single plan when you already know the sku or id, contrasting with 'search_esim_plans' which searches over plans. However, it does not explicitly state when not to use it (e.g., to list all plans) or provide alternatives beyond the sibling list.

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?

With no annotations, description fully discloses behavior: lists possible statuses ('awaiting_payment', 'processing', 'ready', 'expired', 'refunded', 'failed') and instructs agent to never assume payment succeeded. This is thorough for a simple tool.

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?

Description is concise, front-loaded with purpose, and each sentence adds meaningful information. No filler or 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?

Given the tool has only one parameter and no output schema, the description effectively serves as the output schema by enumerating possible statuses and their implications. Covers all necessary guidance for correct invocation.

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%, but the description enhances the parameter by linking it to create_checkout, which adds workflow context. Without this, the parameter is self-explanatory, so baseline 3 + 1 for added value.

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?

Description clearly states 'Fetch the eSIM QR code(s) for an order' with a specific verb and resource. It distinguishes from siblings like create_checkout or get_esim_plan by focusing on QR retrieval linked to a checkout session.

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?

Explicitly says 'to show the buyer directly' and provides a prerequisite: 'Pass the checkout_session_id from create_checkout.' The status descriptions also guide the agent on how to interpret responses.

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?

With no annotations provided, the description carries full behavioral burden. It effectively discloses that the tool has no parameters (empty input_schema), is a read-only informational listing, and produces slugs for a specific purpose. It does not describe the output format or any potential caching behavior, but the simplicity of the tool (0 params) makes this less critical.

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 sentences, no wasted verbiage. The first sentence states the core function, the second provides critical usage guidance. Every word earns its place. Perfectly front-loaded.

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?

Given 0 parameters, no annotations, no output schema, and a simple listing function, the description is nearly complete. The only minor gap is not mentioning whether the list includes all possible destinations or if there are any prerequisites/caching. However, for a straightforward list tool, this is adequate.

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 input schema has 0 parameters and 100% coverage, so the baseline is 4. The description adds value by explaining how the output (slugs) relates to sibling tool input, which is beyond what the empty schema provides. No need for param documentation since none exist.

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 tool lists Alt eSIM destinations including country/region slugs, English names, and region. It distinguishes itself from siblings by explicitly mentioning the output includes slugs that are used as input for search_esim_plans. The verb 'list' is specific and the resource 'Alt eSIM destinations' is well-defined.

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 explicitly tells the agent when to use this tool (to find slugs for search_esim_plans), providing a direct connection to a sibling tool. It lacks explicit 'when not to use' guidance, but the context of usage is clear and actionable.

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?

No annotations are provided, so the description carries the full transparency burden. It discloses that the tool returns plans with specific fields (sku, data amount, validity days, USD price, coverage carriers) and notes that all prices are in USD. This is adequate for a read-oriented search tool, but it does not discuss rate limits, auth requirements, or potential side effects.

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 concise: three sentences, each serving a distinct purpose (purpose, filters, return fields). Information is front-loaded with the primary action. No unnecessary words or repetition.

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?

Given the tool has 3 optional parameters and no output schema, the description covers the essential aspects: what it searches, filters, and returns. It mentions the return fields and price currency. It could be more complete by noting ordering or pagination behavior, but it is sufficient for a simple search tool.

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 baseline is 3. The description adds value by providing concrete examples for the country slug ('japan', 'usa', 'europe') and stating 'Omit to list all', which clarifies behavior beyond the schema. The region enum is also hinted at, though the schema already defines 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?

The description clearly states 'Search Alt eSIM travel data plans' with a specific verb and resource. It lists filter options and return fields, making the purpose clear. However, it does not explicitly differentiate from sibling tools like 'list_destinations' or 'get_esim_plan', which would strengthen clarity.

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 context on what to filter by (country slug, region, max price) and gives examples ('japan', 'europe'). It implies usage for finding plans but does not give explicit guidance on when to use this tool versus alternatives, nor does it mention when not to use it.

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