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

Annotations already cover the read-only, idempotent, non-destructive nature of the tool. The description adds useful context about US-relative price levels and both-direction salary equivalence, but does not disclose additional behavioral traits such as data freshness, coverage caveats, or limits. This is adequate given the annotations.

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 dense, front-loaded sentence that names the action first and then enumerates the distinct outputs. There is no filler or redundant restatement of 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?

For a simple two-parameter read-only tool with annotations and an output schema, the description is largely complete: it names the data sources and the derived metrics. The main missing piece is a brief statement about when to prefer this over sibling comparison tools, which is primarily a usage-guideline gap.

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 is 100%, so both parameters are already documented as ISO alpha-2 country codes with clear constraints. The description adds little beyond confirming 'two countries' and implying a US-relative frame, but it does not clarify the role of a vs. b in the comparison.

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 specific action ('Side-by-side comparison of two countries') and a clear resource: cost-of-living data across named datasets. The output list ('consensus ratio, percent difference, $100k salary equivalence') makes it distinct from sibling tools like compare_climate or compare_healthcare.

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?

There is no guidance on when to use this tool versus alternatives such as compare_total_cost or other compare_* siblings. The recommended use is only implied by the title and description, with no explicit exclusions or routing.

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