compare_countries

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

With no annotations, the description carries the full burden of behavioral disclosure. It clearly indicates a read-only comparison operation and specifies what is compared, but it does not mention return format, behavior on invalid tags, or whether an active save is required. The output schema partially compensates for return-format details, but deeper behavioral context is absent.

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 a single, front-loaded sentence that states the core action and the parameter format with no filler. Every word contributes to the tool's operational meaning, making it highly efficient.

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 the simplicity of the tool—one optional parameter with a schema default and a present output schema—the description covers the essential purpose and parameter format. Minor gaps such as prerequisites or error behavior are not critical for this low-complexity tool, so the definition is nearly 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 description coverage is 0%, so the description must compensate. It adds a clear semantic for the only parameter: tags are comma-separated labels. While it does not explicitly explain that tags are country identifiers, the default value 'CHI,GBR,RUS,FRA,USA,JAP' and the tool name make that inferable. This is sufficient for a single optional parameter.

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 ('对比' / compare) and a resource ('多个国家' / multiple countries), and lists the exact metrics compared: GDP, prestige, population, and technology count. This clearly differentiates it from the sibling 'country' tool, which would handle a single country, and from other metric-specific tools like 'economy' or 'technology'.

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 intended context—comparing multiple countries across several metrics—is implied by the description, and the parameter format 'tags 为逗号分隔标签' gives basic input guidance. However, it does not explicitly state when to prefer this tool over alternatives, such as using 'country' for a single-country analysis, nor does it mention any prerequisites like having a save loaded.

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