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

Annotations already cover read-only, idempotent, non-destructive, and open-world behavior, so the safety profile is clear. The description adds useful context beyond annotations: it states that the tool returns current public offers, plan details, coverage, pagination, and notes that fixed bundles retain actual validity. This is meaningful extra behavioral information.

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 front-loaded sentences with little waste. It states the main listing inputs first and the return behavior second. The phrase about fixed bundle validity is slightly cryptic but still relevant and compact.

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 tool with nine parameters, low schema description coverage, and no output schema, the description is not complete enough. It explains the high-level return content but omits guidance on several optional parameters, especially the alternatives-related ones that likely matter for comparison workflows.

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 very low (11%), so the description must compensate. It covers destination, duration, currency, and data preference at a high level, but leaves several parameters unexplained, including locale, limit, offset, includeAlternatives, and alternativesForPlanId. Pagination is mentioned only as a return feature, not as a parameter behavior.

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 a specific verb and resource: list Roamzo travel eSIM plans. It also names the main scoping inputs (destination, duration, data preference, currency), so an agent can understand the tool's role. However, it does not explicitly distinguish this listing tool from siblings such as compare_esim_prices or get_esim_plan.

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 explicit guidance on when to use this tool versus alternatives like compare_esim_prices or get_esim_plan. It describes the listing behavior and inputs but leaves the agent to infer when this tool is the right choice.

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