search_esim_plans

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It discloses that results contain the full plan shape, including specific features, so the agent knows no additional details call is needed. This goes beyond the schema, but it does not mention pagination behavior, rate limits, or other side effects, which are not critical for a search 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?

The description is one well-structured sentence that front-loads the core purpose and then packs useful details about output shape. Every word earns its place, and the parenthetical list is concise yet informative. No redundancy or unnecessary padding.

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 the tool has 8 optional parameters, no output schema, and no annotations, the description provides useful context about return values (full plan shape) but misses guidance on pagination (cursor), filter usage, sorting, or how to combine filters. It is functional but not complete for an agent to take full advantage of the tool.

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 schema description coverage is only 25% (query and country have descriptions). The tool description focuses entirely on output shape and does not add meaning to input parameters like has_5g, has_hotspot, min_data_gb, min_days, limit, or cursor. With low schema coverage, the description should compensate but fails to explain filters or pagination semantics.

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 clearly states 'Search global eSIM data plans' with a specific verb and resource, and it distinguishes this tool from siblings like search_sms_services and search_dedicated_countries by focusing on eSIM plans. It also clarifies that results include the full plan shape, further differentiating it from any potential plan-details 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?

The description implies usage when searching for eSIM plans and explicitly notes that a separate plan-details tool is unnecessary. However, it does not explicitly state when this tool should be used versus alternatives like purchase_esim or get_esim_status, nor does it mention exclusions for other search tools.

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