SimAbroad eSIM

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), and the description adds real value on top: what happens when the link is opened (plan added to cart, checkout flow), accepted payment methods, QR delivery by email, and the reassurance that calling the tool charges nothing. It does not cover link expiry or whether the URL is single-use, which would be the remaining operational detail.

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 tightly packed sentences: purpose and input source first, then downstream behavior, then the no-charge caveat. No filler, and the most decision-relevant information is 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?

With no output schema, the description carries the burden of explaining what the agent gets back and what happens next (a checkout link, payment, emailed QR code) and it does so completely. Nothing needed to call this two-parameter tool correctly 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 description coverage is 100%, so both parameters are already documented, including the allowed languages and the id source. The description reinforces package_id provenance but adds nothing about the language parameter or format syntax beyond the schema. 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 and resource ('Get a simabroad.com checkout link for one eSIM plan') and ties the input to its origin tool, naming search_esim_plans explicitly. An agent can distinguish this from list_destinations and search_esim_plans without opening a schema.

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?

Clearly states the context of use: call it with the id returned from search_esim_plans to hand a traveler a checkout link. It implies the alternative (search first, then link) but never states an explicit exclusion or fallback, so it falls just short of a 5.

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, non-destructive and closed-world, so safety is covered. The description adds real value beyond that: availability is current ('right now'), search accepts aliases like 'USA'/'UK' as well as codes, and destinations carry a multi_country_only flag — behavioral details the annotations cannot express.

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, all front-loaded — purpose first, then the practical handoff to search_esim_plans, then the caveat. No filler or restated schema.

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 usefully explains what comes back (countries/regions plus country_code, and the multi_country_only marker). A hint about pagination or result size would make it fully complete, but for a 2-param read-only lookup this is close to sufficient.

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; baseline is 3. The description reinforces that the search parameter tolerates names, aliases and codes, but adds no format constraints or examples beyond the schema's own text.

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 ('List countries and regions where SimAbroad sells eSIM plans right now') and immediately ties itself to the sibling search_esim_plans via the returned country_code. An agent can distinguish it from get_buy_link and search_esim_plans without opening a schema.

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?

Clear usage context: this is the lookup step whose country_code feeds search_esim_plans, and it warns that multi_country_only destinations can't be booked with country plans. It does not explicitly state when NOT to call it or name an alternative list tool, 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 cover readOnly/idempotent/openWorld=false. The description adds real context beyond them: results are filtered to plans on sale now, sorted cheapest-first, priced in USD charged at checkout, and each carries a buy_url for that exact plan.

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 with the core action and the primary parameter, then layered with parameter guidance and return behavior. Dense but each sentence carries information; slightly long, keeping it from a 5.

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 an 8-parameter, no-output-schema tool, it covers parameter routing, filtering, sort order, currency, and return fields (buy_url, coverage). An agent has everything needed 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 coverage is 100%, so baseline is 3; the description nonetheless adds meaning by explaining that country_code accepts ISO or catalogue codes and returns single-country plus regional/global plans (with a coverage field), and that region targets multi-country plans.

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 (search) and resource (SimAbroad eSIM plans) with a clear scope (for a trip). It is easily distinguished from siblings: it references list_destinations as the source of codes and get_buy_link implicitly via the buy_url/checkout behavior.

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?

Gives clear routing between country_code and region ('Or pass region for multi-country plans') and explains how to use min_validity_days/min_data_gb/unlimited. It lacks explicit when-not-to-use guidance or a named alternative for other flows, so it stops short of a 5.

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