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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so the safety profile is covered. The description adds value beyond them by disclosing the return contract ('valid true/false with the reason') even though no output schema exists, and openWorldHint=false is consistent with a closed lookup of Hoplix's served-country list. It does not say whether the check is a static list or a live carrier lookup, which would have made it a 5.

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, zero waste, with the validation conditions front-loaded and the return behavior stated second. Nothing is repeated from the schema 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 single nested-object parameter with full schema coverage, the definition covers what is checked and what comes back. The remaining gap is that 'the reason' is uncharacterized (free text? enum of failure codes?), which matters since there is no output schema to fall back on.

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 every nested field, including province and country-code formats, is documented in the schema itself. The description only gestures at 'complete' and 'destination country' without adding format or validation semantics, so the 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 and resource ('Checks whether a delivery address is complete') plus the second condition it tests (destination country served by Hoplix). It is clearly distinct from the order/campaign siblings, though it never explicitly contrasts itself with quote_order or create_order, which are the tools most likely to consume this result.

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?

No explicit when-to-use statement, no prerequisites, and no named alternatives. The purpose implies a pre-flight validation step before quote_order/create_order, but the agent must infer that; the description never says when this check should be run or what to do with a false result.

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