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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds meaningful behavioral context by clarifying that 'language is detected from the actual query text' rather than the embed/browser setting, which shapes how the agent should interpret results. This goes beyond the annotation safety information.

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?

Two compact sentences with no filler. The core definition is front-loaded first, and the sibling distinction is stated concisely with a practical example. Every sentence contributes decision useful information.

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 read-only analytics tool with a full input schema, an output schema, and safety annotations already present, this description is complete. An agent knows what is measured, how it differs from its nearest sibling, and when to use both. No critical gap remains.

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 100%: both limit and time_filter are already fully documented with defaults, types, and allowed values. The description adds no additional parameter-level semantics beyond what the schema provides, so the baseline of 3 is appropriate.

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 the resource ('top detected natural languages of user CHAT questions'), the operation ('ranked by occurrence count'), and explicitly differentiates from the sibling tool get_top_locales. An agent can immediately distinguish this analytics-read tool from the similar locale tool without opening schemas.

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?

It tells the agent when to prefer this tool over get_top_locales and how to use both together ('Use both to spot mismatches'), including a concrete example. This is explicit alternative guidance beyond a mere definition.

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