Simsima Connectivity

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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and openWorldHint=false, so the safety profile is covered. The description adds genuine context that the destination argument accepts a country, region, or global plan, but says nothing about the shape of the answer or how ambiguous country input is resolved.

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 zero filler; the core purpose leads and the accepted input forms follow immediately. Nothing is redundant against the title or 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?

For a simple read-only coverage check with no output schema, the description gives enough to call the tool correctly, including valid input forms for both required parameters. The main remaining gap is that it never characterizes the response (boolean vs. coverage detail), which matters slightly when no output schema exists.

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 only 33% (locale is documented; country and destination are bare), so the description carries real weight here: it explains that country may be a name or ISO code and that destination spans country, region, or global plan. This meaningfully compensates for the undocumented required parameters, though it does not spell out locale's role.

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 — answering whether a destination covers a country — and frames it as the user-facing question it resolves ("does this eSIM work in <country>"). It is clearly distinct from siblings like get_destination_info or list_destinations, though it never names them, so 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?

The framing implies the use case (a yes/no coverage question for a plan, region, or global destination), which is enough to infer when the tool applies. However, it gives no explicit when-not guidance and never points to alternatives such as get_destination_info for richer detail or list_destinations for enumeration.

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, and destructiveHint=false, so the safety profile is covered; the description adds domain-specific value with 'No order is placed and no payment is made by this tool,' directly countering the transactional implication of the tool name. Auth requirements and link expiry are still undisclosed.

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 tight sentences with no waste: purpose first, then the non-transactional clarification, then the parameter behavior. Every sentence earns its place and the most important constraint (no purchase) is front-loaded after the purpose.

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 does state what comes back (a URL) and how the two parameter modes shape it, and annotations cover safety. Minor gaps remain around link lifetime and the source of valid sku/destination values.

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 only 33% (only locale is documented), so the description must carry sku and destination — and it does, explaining that sku selects the plan and destination alone produces an unpreselected page. It does not say where sku/destination values come from or their format, so it is not fully compensating.

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: 'Return the URL of a plan's page on simsima.io, with the plan preselected.' It also preempts the misleading 'checkout' name by clarifying it is a link generator, not a purchase. It does not name or contrast any sibling tool, so it stops short of a 5.

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 delineates the two invocation modes: pass a sku to preselect a plan, or pass only a destination to land on a destination page with no plan. That is actionable context, but it never states when to choose this tool over siblings like get_plan or recommend_plan.

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 the safety profile (readOnlyHint, idempotentHint, destructiveHint=false, openWorldHint=false), so the description's real job is describing what comes back, and it does list the returned data categories. It stops short of return shape, pagination or how a missing/unsupported destination behaves, so it adds moderate value rather than rich context.

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 dense sentence that front-loads the returned data categories with zero filler. It lacks a leading verb, which slightly hurts readability, but nothing 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 is the only source for return content, and it gives a reasonable field inventory. However, it omits the destination input format and any usage boundary against check_coverage, leaving the agent with unresolved ambiguity for a tool in a crowded sibling set.

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 only 50%: locale is thoroughly documented in-schema, while destination has no description at all. The phrase 'Coverage (ISO country codes)' is ambiguous about whether ISO codes describe the destination input format or the returned coverage, so the description only partially compensates for the gap.

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 enumerates exactly what the tool returns for a destination: coverage, mobile operators, top-up availability and entry price. That is a clear resource-and-attributes statement, but it never contrasts itself with the sibling check_coverage, which on name alone sounds like it may overlap.

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 prerequisites, and no routing to alternatives such as check_coverage, list_destinations, or search_plans. The agent is left to infer usage entirely from the name and the list of returned fields.

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 openWorldHint=false, so the safety profile is fully covered elsewhere. The description adds no behavioral context of its own: it says nothing about error behavior for unknown skus, response latency, or what the returned plan object contains. With no output schema, that is a missed opportunity rather than an error.

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 zero filler: verb, resource, key, and provenance. Nothing repeats the title or annotations.

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 read-only detail lookup the safety and identity story is complete, but with no output schema and no description of the returned plan fields, an agent cannot anticipate what a successful call yields or how to handle an invalid sku. Adequate, not complete.

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 50% (locale is richly documented in the schema, sku is not). The description does compensate partly for the undocumented sku by telling the agent where the value originates (search_plans/recommend_plan), which is genuinely useful. It adds nothing about locale, which the schema already handles.

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?

Names a specific verb (Get) and resource (one eSIM plan) plus the identifying key (sku), and ties the tool to its place in the workflow by noting the sku comes from search_plans or recommend_plan. It never explicitly contrasts itself with siblings like get_destination_info, but the resource is unambiguous.

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 phrase 'as returned by search_plans or recommend_plan' establishes the precondition for calling it: you already have a sku from a prior search or recommendation. There is no explicit when-not guidance, but the usage context is clear enough for an agent to route correctly.

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=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered. The description adds only the content of each entry (entry price, product URL) and says nothing about catalog size, pagination, or price semantics (e.g. cheapest-plan entry price), which are the remaining behavioral questions for this 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?

One sentence, front-loaded with the verb and resource, with the scope and returned fields in a compact parenthetical. Nothing is redundant or padded.

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 read-only catalog listing with full parameter documentation and no output schema, the description adequately conveys what is returned and what the list spans. It stops short of addressing pagination or catalog size, which an agent browsing a global destination catalog might need.

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?

There is a single optional parameter, and schema description coverage is 100% — the schema fully documents that locale sets product-page language and price currency. The description does not mention locale or its currency side effect at all, so it adds no meaning beyond the schema; baseline 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?

States a specific verb ('List') and resource ('destinations Simsima covers') and enumerates the coverage scope (countries, regions, global plans) plus the returned fields (entry price, product URL). It is clearly distinguishable from single-target siblings like get_destination_info or search_plans, though it never names them 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?

Usage is only implied: the phrasing 'destinations Simsima covers' signals a full-catalog browse as opposed to search_plans or recommend_plan, but no explicit when-to-use, when-not-to-use, or alternative is given. The agent must infer routing from the sibling names alone.

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 the safety profile is fully covered. The description adds only the vague notion of 'best plan(s)', implying ranked results, but discloses nothing about ranking criteria, how many plans return, or what happens when no plan fits.

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 that names the action, the resource, and the qualifying inputs with zero filler. Nothing is wasted or buried.

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 read-only recommendation tool with no output schema, the description covers the required inputs adequately but omits what the recommendation actually returns (list of plans with prices?) and how 'light/medium/heavy' map to data allowances. Adequate but with clear gaps.

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 only 25%, so the description must compensate. It does explain tripDays and usage (light/medium/heavy as expected data usage), which maps the required inputs, but it says nothing about destination format (country/region code?) or the locale parameter's dual role of language and currency. Partial compensation, hence 3.

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 (Recommend) and resource (best plan(s)) plus the three inputs that drive it (destination, trip length, usage level). It is clearly a recommendation tool rather than a raw lookup, which helps distinguish it from search_plans/get_plan. It stops short of explicitly naming those siblings, so it doesn't fully earn a 5.

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 trip-planning framing implies when to call it, but there is no explicit when-to-use vs. when-not, and no mention of the very close sibling search_plans. An agent must infer that this is the higher-level 'advise me' entry point versus the lower-level search/list tools.

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 the safety profile (readOnlyHint, idempotentHint, destructiveHint=false, openWorldHint=false). The description adds real behavioral context beyond them: results are returned cheapest-first, and the destination can be a country, a region, or global. It still omits result limits or pagination 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?

A single sentence with zero waste: verb+resource first, then scope, then sort order, then filter options. Nothing is repeated from the title or schema and every clause carries information.

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 6-parameter search tool with 17% schema coverage and no output schema, the description leaves gaps: result shape, result count/pagination, and the unit/currency meaning of the numeric filters are unaddressed. The cheapest-first ordering and destination granularity are useful, but not enough to be fully self-contained.

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 only 17% (only locale is documented), so the description must compensate. It partially does by naming the filter dimensions — price, data, validity, unlimited — which map to maxPrice, minDataGB, maxValidityDays and unlimited, but it adds no units, currency semantics, or confirmation that destination 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?

States a specific verb and resource ('Search the eSIM plans'), names the scope of the destination (country, region or global), and discloses the sort order and filter dimensions. It is clearly distinguishable from get_plan, but it never explicitly names or contrasts with the siblings (recommend_plan, list_destinations).

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 the usage context (search plans for a destination with optional filters) but gives no explicit when-to-use guidance, no exclusions, and no mention of how it relates to alternatives like recommend_plan or get_plan. An agent must infer the routing decision entirely.

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