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 does reveal that results are side-by-side and ranked in EUR, which is useful context. However, it does not specify sort direction, response structure, data source, or error 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?

One sentence with no filler, front-loading the core comparison purpose and then stating the ranking rule. Every element earns its place.

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?

There is no output schema and no annotations, so the description must explain return behavior. It covers side-by-side presentation and EUR pricing but leaves sort direction and response structure ambiguous. For a simple single-parameter tool this is near adequate but not fully 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 for the only parameter is 100%, already documenting ISO 3166-1 alpha-2 country codes with min/max constraints. The description adds conceptual context about readings but does not contribute parameter-level meaning beyond what the schema provides.

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 concrete outcome: 'Side-by-side omelette index readings for two or more countries, ranked by price in EUR.' It clearly distinguishes this multi-country comparison tool from single-country siblings like country_index.

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 'for two or more countries' implies the tool is for comparing multiple countries, but there is no explicit statement of when not to use it or which sibling tool to use instead for a single country. Usage guidance is inferable rather than stated.

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