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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=true, and destructiveHint=false, so the safety and idempotency profile is fully covered. The description adds billing context (usage-based, ~$0.012 estimate), which is genuinely useful behavioral information not in the annotations, but says nothing about auth or rate limits.

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 second sentence about JSON-encoded data and a tasks array duplicates what the existing output schema already conveys, and the multi-line pricing comment block is verbose boilerplate. Only the first sentence is load-bearing, so the definition is padded rather than front-loaded.

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?

With zero parameters, a rich annotation set, and an output schema present, the description only needs to state purpose and cost, which it does. It could still note that this is a static, parameter-free reference lookup to be used before language-scoped content calls, which would close the remaining 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?

The tool takes zero parameters, so the baseline is 4; there is nothing for the description to disambiguate. The statement about receiving a tasks array does not add parameter meaning, but none is needed here.

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 resource (the list of languages) for a specific API (Content Analysis), which is clear enough to identify the tool. However, it does not differentiate itself from closely related lookup siblings such as get_dataforseo_content_locations or get_dataforseo_content_categories, so an agent must infer the distinction from names alone.

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 call this tool versus the other reference-list siblings, nor any stated prerequisites or sequencing (e.g., call before content search to resolve a language code). The description merely asserts what you receive, leaving usage entirely to inference.

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