List languages

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

Annotations already cover the safety profile (readOnly, idempotent, openWorld, non-destructive). The description adds value beyond them by disclosing the return shape ('codes and names') and confirming the call is parameter-free, though it says nothing about caching, rate limits, or ordering of the returned list.

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 front-loaded Overview is good, but four markdown sections for a zero-parameter reference call is heavy, and the return content (language codes and names) is restated in both 'What You Get' and 'Quick Start'. Some sentences do not earn their 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?

For a simple reference endpoint with no parameters, no output schema, and full annotation coverage, the description supplies everything needed: purpose, usage contexts, and the shape of the returned data. Nothing an agent needs to call it correctly is missing.

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?

With zero parameters the baseline is 4, and the description correctly confirms 'No parameters required,' leaving nothing ambiguous for the caller. There is no parameter detail to add beyond that.

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 Overview states a specific verb and resource: 'Get all supported languages for hotel translations and content localization.' It also names the practical purpose (language codes for API requests), which cleanly distinguishes it from the other get_data_* reference tools such as currencies or countries.

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 'When to Use' section gives four concrete triggering scenarios (language selection UI, content localization, multi-language support, reference validation). It is clear about context but never names a when-not condition or an alternative tool, which is the only thing keeping it from a 5.

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