check_expansion_eligibility

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

Without annotations, the description should disclose behavior. It does not explain what the tool returns (e.g., boolean, list, details) or any side effects. The output schema exists but is not described, so the agent lacks key behavioral cues.

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?

While the phrase is short, it is under-informative. Conciseness should not sacrifice content; here it sacrifices all useful information beyond 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?

Given two required parameters with no schema descriptions and an undeclared output schema, the description fails to provide enough context for correct invocation. The agent cannot determine expected input formats or output structure.

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 0%, so the description must add meaning to parameters. It does not: 'asin' and 'marketplaces' remain undefined. No format hints (e.g., comma-separated country codes) are given.

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 'Elegibilidad para vender en otros marketplaces EU' clearly indicates the tool checks eligibility to sell in other EU marketplaces. It aligns with the tool name and distinguishes it from price- or restriction-checking siblings.

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 guidance is provided on when to use this tool versus alternatives like check_listing_restrictions or get_cross_marketplace_prices. The description lacks any context for selection.

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