Slashtel

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and non-destructive, which are consistent with generating a link rather than creating a server-side record. The description adds real behavioral context beyond annotations: the payment happens off-platform and the link is meant to be shared with the user.

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 outcome (a link), then the user flow, then the parameter branching. No 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?

With no output schema, the description correctly states what is returned (a link URL) and how the consumer uses it. It covers the composite parameter requirements for both enum branches. Minor gap: no mention of error/failure behavior, but otherwise complete for the task.

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 80%, but the description adds the key conditional logic the schema cannot express — which parameters to pass based on the 'type' enum value. That mapping (esim→plan_id; topup→phone/operator_code/send_value) is genuine value beyond the field descriptions.

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 (returns a slashtel.com link) with the scope of what's pre-selected (eSIM plan or top-up). The mention of get_topup_plans and get_esim_plans implicitly distinguishes it from the plan-listing siblings, so an agent can tell it isn't a lookup tool.

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 workflow guidance — share the link, user enters email and pays on site — and branches by type ('esim' → plan_id; 'topup' → phone, operator_code, send_value). It lacks explicit when-not-to-use conditions, but the conditional parameter routing is strong usage 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 declare readOnlyHint, idempotentHint, destructiveHint=false and closed-world, so the safety profile is covered. The description adds non-annotation context: results are 'live' (current pricing), priced in USD, and normalize to a price-per-GB figure. It stops short of describing pagination or result limits.

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 tight sentences with no filler: the first front-loads what is returned, the second covers the required destination format and optional filters. Every clause earns its place.

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 return-shape burden and does so by naming the four returned attributes. Combined with the 100%-covered input schema and explicit code-source guidance, an agent has everything needed to call this 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 description coverage is 100%, so the schema already documents all three parameters, giving a baseline of 3. The description adds mild value by clarifying that destination accepts an ISO-2 code or a code from list_esim_destinations and that min_gb/min_days narrow the list, but this largely restates the schema.

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 (live travel eSIM plans for one destination) and enumerates the returned fields: data GB, validity days, price USD, price per GB. It distinguishes itself from list_esim_destinations by referencing it as a code source, but does not explicitly differentiate from the sibling get_topup_plans.

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 guidance: supply an ISO-2 country code (with examples TR, JP, US, GB) or a destination code obtained from list_esim_destinations, and notes the filters are optional narrowing. No explicit when-not-to-use or alternative-selection rule, but the context is clear.

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, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds genuine context beyond that: it discloses that the call performs operator detection and returns recipient value, validity and USD price, which tells the agent what the response contains.

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 compact sentences, front-loaded with the core action and followed by the return contents and the input constraint. No filler; it could be marginally tighter but nothing wastes space.

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 one-parameter read-only lookup with no output schema, the description covers enough: it names the return fields and the input format requirement. Missing only pagination/availability caveats, which are minor for this shape.

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% and the single 'phone' parameter is already documented as a full international number. The description reinforces the country-code requirement and adds the concrete example +911234567890, which is mild added value over the schema but not substantial.

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 specific verbs and resources: detects the operator of a mobile number and returns live top-up options. The 'top-up' framing separates it from the sibling get_esim_plans, but the description never explicitly contrasts the two product lines, so an agent must infer the distinction.

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?

Implies when it applies (you have a mobile number and want top-up options) and gives a hard prerequisite — the number must include the country code. It offers no explicit when-not-to-use or routing against get_esim_plans / create_checkout_link, so guidance stays implied.

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 declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is fully covered elsewhere. The description adds useful behavioral context about the return payload (live lowest price, plan count) but says nothing about pagination, result ordering, or how 'live' pricing is refreshed.

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?

One sentence with the resource front-loaded, followed immediately by what distinguishes the results and the optional filter. No filler or redundant restatement of the title.

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 available, the description usefully enumerates what each entry contains (lowest live price and number of plans), which is exactly the gap it needs to fill. Coverage is close to complete for a simple one-parameter list tool, with only refresh/pagination behavior left unstated.

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 the single 'search' parameter is already documented with examples in the schema. The description's 'filters by name' merely restates that, adding no new syntax or matching semantics, so the baseline of 3 applies.

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 resource (countries and regions Slashtel sells travel eSIMs for) and the exact payload it returns (lowest live price in USD plus plan count), which is far more concrete than the tool name alone. It does not, however, explicitly contrast itself with the sibling get_esim_plans, so the boundary between browsing destinations and browsing plans must be inferred.

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 mentions that an optional search filters by name, but never states when to reach for this tool versus get_esim_plans or the topup variants. An agent gets a sense of the tool's content but no routing guidance or prerequisites.

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