visa-requirements

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

With no annotations, the description carries the full behavioral burden. It usefully discloses that answers are contingent on passport and entry route, and the informational framing implies a read-only lookup, but it says nothing about the shape of the answer (per-route rules, cost currency, processing steps) beyond the vague 'how'.

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 with no filler, and the scope statement is front-loaded before the constraint. It is efficiently sized, though the second sentence is doing double duty as both justification and parameter guidance.

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 two-parameter lookup with no output schema and no annotations, the description is serviceable but thin. It does not resolve the destination-vs-entry-route ambiguity or hint at what a qualifying answer contains, which matters because nothing else in the structured data fills that 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 coverage is 0% for both parameters, so the description must compensate. It does explain why both are required (rules vary by passport and entry route), giving passport clear meaning, but 'destination' is never defined relative to 'entry route', leaving genuine ambiguity about what value to pass.

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 names a specific informational resource — whether and how a stay can be extended, including duration and cost — which distinguishes it from siblings like visa_lookup and passport_power. It stops short of explicitly contrasting itself with those siblings, so it is clear but not fully differentiated.

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 implied: this is the tool to consult for extension questions, and the description notes results vary by passport and entry route. However, it never states when to choose it over visa_lookup or list_destinations, nor any exclusions, leaving the agent to infer routing between siblings.

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 behavioral burden and fails it: nothing is said about whether the result is exhaustive, whether it is cached/static, pagination, or auth requirements. The only behavioral hint is 'with slugs', which implies the payload includes a slug identifier alongside destination names, and that is barely one step beyond the schema.

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 six-word fragment with no filler, and the scope qualifier is front-loaded. It is efficient, though it is a noun phrase rather than a sentence, which costs it a point on structure rather than brevity.

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?

There is no output schema, no annotations, and no parameters, so the description is the only carrier of information, yet it never describes the shape of the returned list (e.g. array of {name, slug} objects) or its completeness. For a reference-data listing tool whose only value is what it returns, this is under-specified.

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 defines zero parameters, so there are no parameter semantics to clarify and the baseline of 4 applies. The description does not need to explain arguments and correctly does not invent any.

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 fragment names the resource ('destinations') and the scope ('all supported') plus the key returned field ('slugs'), so an agent knows this is a listing of all destinations. However, there is no verb and no differentiation from siblings such as list_nationalities or visa_lookup, which are structurally similar lookups in the same visa/travel domain.

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 call this versus the sibling lookup tools. 'All supported destinations' implies a bulk-enumeration use case but never states it as a condition selecting this tool over visa_lookup or passport_power.

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, the description carries the full burden, but for a zero-parameter read-only reference list the risk surface is small. It discloses the payload ('passports with ISO codes') which is the main behavioral fact; it does not state whether the list is static, cached, or whether it includes all nationalities or only supported ones (a meaningful distinction it raises but never resolves).

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 short sentence with no filler, front-loaded with the resource. It is terse to the point of omitting a verb, but there is no wasted text.

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, no-output-schema enumeration, the description covers what an agent needs to call it and what it returns. It could resolve the nationality-vs-passport naming mismatch and note whether results are exhaustive, but the gap is minor for a tool this simple.

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 tool takes zero parameters, so the baseline is 4; there are no parameter semantics to clarify or omit. The description adds nothing here because nothing is required.

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 the resource ('all supported passports with ISO codes') but omits the verb and does nothing to distinguish it from list_destinations or other sibling listing tools. An agent can infer it is a reference enumeration, but cannot tell from the text how it differs from list_destinations or nationality-related siblings.

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?

There is no when-to-use guidance, no stated relationship to siblings like visa_lookup or passport_power, and no conditions or exclusions. Usage is only weakly implied by the word 'supported'.

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 behavioral burden. It implies a read-only aggregate and hints at the return shape ('grouped and counted'), but says nothing about whether the passport is required, whether results are ranked, what visa categories exist, or any rate/auth constraints.

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 with no filler; the aggregation behavior is the most useful part and is not buried. It is arguably too terse for the gaps it leaves, but nothing in it is wasted.

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 sketches the return shape ('grouped and counted by visa category'), which is more than most one-liners offer. However, for a lookup tool with an undocumented parameter format and no annotations, it falls short of what an agent needs to call it confidently.

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 0% and the single required parameter 'passport' has no type detail beyond string and no documented format. The phrase 'on one passport' hints at a single value and implies a country/entity identifier, but the description never states the expected format (ISO code, nationality name, etc.), leaving a real ambiguity for the agent.

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 resource (destinations reachable on a passport) and a specific output shape (grouped and counted by visa category), which distinguishes it from siblings like visa_lookup and list_destinations. It stops short of explicitly naming those siblings, so the differentiation is implicit 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?

There is no when-to-use guidance, no when-not-to-use, and no reference to any alternative tool, despite four sibling tools that overlap conceptually (visa_lookup, list_destinations, list_nationalities, extension_rules). An agent must infer the use case entirely from the description sentence.

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, the description carries the full burden. It discloses the returned data fields well, which is helpful for a tool lacking an output schema, but it omits behavioral details like whether results are live or cached, rate limits, or error handling. The 'always pass both arguments' constraint is a minor behavioral note.

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 first sentence efficiently lists the return fields, and the second is a short constraint. It is front-loaded with the core purpose and avoids unnecessary verbosity, though the closing argument reminder is slightly redundant given the schema's required flags.

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 no output schema, the description usefully enumerates the return payload, which an agent would otherwise have to infer. It covers the essentials for calling the tool, though it could briefly mention the optional language parameter's effect or error behavior for full completeness.

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 input schema already fully documents all three parameters with examples. The description adds 'Always pass both arguments,' which is redundant with the required fields, and provides no extra syntax or format guidance beyond what the schema supplies.

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 resource (visa requirement) for a passport+destination pair and enumerates the returned fields (category, fee, processing time, etc.), making the tool's scope clear. It does not explicitly differentiate from siblings like extension_rules or passport_power, but the lookup nature is distinct.

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 only guidance is 'Always pass both arguments,' which addresses parameter usage rather than when to choose this tool over alternatives. No context about when to use it versus siblings such as extension_rules or list_destinations is provided.

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