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

With no annotations and no output schema, the description carries the full behavioral burden, yet it discloses only the 2-4 country constraint. It says nothing about read-only nature, what the side-by-side output contains, rate limits, or the meaning of 'published content topic' (e.g., where the content comes from).

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?

A single front-loaded sentence with no filler; the comparison action and the cardinality constraint are stated immediately. It is efficient, though it may be too terse given the undocumented parameters.

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 3-parameter tool with zero schema documentation, no annotations, and no output schema, the description is insufficient. It omits parameter meaning and any sense of the returned comparison, leaving an agent guessing about invocation details beyond the country count.

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 0%, so the description must compensate, and it only partially does: it conveys the countries cardinality (2-4) while leaving 'lang' and 'topic' (defaulting to 'summary') entirely unexplained. An agent cannot tell what values 'topic' accepts or how 'lang' affects 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 verb ('compare') and resource ('one published content topic') scoped to countries, which separates it from single-country siblings like get_country_facts and get_country_guide. However, it doesn't explicitly name those siblings as the alternative, so differentiation is inferred rather than stated.

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 sentence implies when this tool is appropriate (multi-country comparison, capped at two to four countries), but gives no explicit guidance on when to prefer it over get_country_facts, get_country_guide, or search_countries. No prerequisites, exclusions, or alternatives are mentioned.

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