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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false, so the safety profile is fully covered by structured data. The description adds only that the response is JSON with a tasks array, and that boilerplate is questionable for a static language-list endpoint (there is no user-supplied task set here), so it adds little while being slightly inaccurate.

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 first sentence directly states the outcome. The second sentence is generic DataForSEO boilerplate about a tasks array that does not describe this endpoint's actual response and does not earn its place, and the inline pricing block further dilutes the text.

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?

An output schema exists, so the description is not obliged to explain return values — yet it spends its second sentence doing so, and inaccurately. For a zero-parameter lookup this is minimally sufficient, but the space could have been used to distinguish this tool from its metadata siblings, which it fails to do.

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 per the rubric the baseline is 4. There is nothing for the description to compensate for, and no parameter ambiguity exists.

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 conveys that the tool returns a list of languages, matching the title. However, it does not state a clear verb+resource framing, and it offers no differentiation from closely named siblings such as get_dataforseo_on_page_lighthouse_versions or get_dataforseo_on_page_lighthouse_audits, which are also static metadata lookups.

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, what preconditions apply, or which sibling to use instead. The reader is left to infer the entire usage context from the tool name and title alone.

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