AeroCell: eSIM Travel Data

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

Annotations already declare read-only, non-destructive, open-world behavior, so the description only needs to add operational context. It does so by disclosing the default filtering behavior ('plans covering the whole trip are returned by default') and how optional filters interact, though it says nothing about result ordering or empty-result behavior.

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 usage rules, then filter behavior. No filler 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?

An output schema exists, so return values need not be explained, and annotations cover the safety profile. The description is complete for calling the tool correctly; the only gap is the absence of explicit routing guidance among the three sibling search/get tools.

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 all seven parameters are already documented. The description restates the country-code format and the date/filter roles, and clarifies that coverage filtering is the default, but adds no syntax or edge-case detail the schema lacks. Baseline 3 applies when 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?

States a specific verb and resource ('Find current AeroCell travel eSIM plans') plus scope ('for one country'), which implicitly separates it from find_regional_esim_plans. It never names the sibling explicitly, so the differentiation is inferred rather than stated.

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 concrete usage instructions: use a two-letter ISO code, supply both travel dates if known, and use filters to narrow. It stops short of explicitly saying when to prefer find_regional_esim_plans or get_esim_plan instead.

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, openWorld and non-destructive, so the description is free to add real semantics — the AND-match rule across country_codes, the fact that a region-only search returns exact country coverage, and that results are "live" bundles. It adds no auth, rate-limit, or pagination context, which is the remaining gap.

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 written sentences, front-loaded with the verb and resource, then the required input rule, then the optional mode. No repetition of schema or annotation content.

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?

An output schema, full annotation coverage and 100% schema descriptions carry most of the load, and the description covers the non-obvious matching logic. The interaction between country_codes and region when both are provided is the one behavioral detail an agent must still guess at.

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 3 is the baseline; the description earns above that by explaining the conjunctive matching semantics of country_codes and the returned coverage for region-only queries. It does not clarify what happens when both country_codes and region are supplied (narrow vs. override), which is the one semantic still ambiguous.

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 ("Find live multi-country AeroCell bundles") and the multi-country qualifier immediately separates it from find_esim_plans and get_esim_plan. An agent can tell what this tool retrieves without opening the 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?

Gives explicit operating instructions: pass every itinerary country as ISO codes, and bundles must list all of them to be returned; a region-only search is also described as a valid mode. It never names find_esim_plans or states when to prefer that sibling, so the routing rule is clear but not exhaustive.

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 establish that this is a read-only, non-destructive, open-world operation. The description adds that the result includes current details and a checkout link, but it does not disclose any further behavioral traits such as link expiration, authentication requirements, or error behavior when the country code mismatches.

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 two short sentences, front-loaded with the tool's core output and followed by the key usage constraint. There is no wasted language.

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?

An output schema exists, so return values need not be described. The description covers the essential retrieval scope and the country-code coupling; the main remaining gap is that it does not explicitly state whether regional plans are out of scope or what happens if the pair is mismatched.

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%, and both parameters are fully documented in the input schema. The description reinforces the coupling between plan_id and country_code, but this is already stated in the plan_id schema description, so it adds little beyond the structured fields.

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: get current details and an AeroCell checkout link for a plan ID. It also scopes the tool to plans from a single-country search, which implicitly distinguishes it from the broader sibling search tools, but it does not name those siblings 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?

It gives clear context for use: the plan ID must come from a single-country search and the same country code is required. It does not explicitly name alternatives such as find_esim_plans or find_regional_esim_plans, but the single-country constraint provides a meaningful usage boundary.

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