keyword_difficulty

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

The annotations declare readOnlyHint=false, idempotent, non-destructive and open-world, but do not explain why a lookup is not read-only. The description supplies that context: the SANDBOX mode returns dummy data with no payment, which implies a paid upstream call in production, and it notes not_found handling in the response. It stops short of stating rate limits or cost behavior per request.

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?

Three short, front-loaded sentences with no filler: what it returns, then the sandbox caveat. Minor choppiness in the 'Returns:' fragment, but every sentence carries 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?

With no output schema, the description at least names the response keys (keywords, not_found) and explains the sandbox/production distinction. For a 3-parameter, single-purpose lookup tool, this covers nearly everything an agent needs, though it omits per-call cost or error semantics for the paid path.

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%, so the schema already documents keywords, language_code and location_code in detail, including defaults, location codes and validation. The description only restates the 100-keyword cap, adding nothing beyond the schema. Baseline 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?

States a specific verb+resource: 0-100 keyword difficulty scores for up to 100 keywords via DataForSEO Labs Bulk Keyword Difficulty. Clear about what the tool produces, but does not distinguish it from siblings like keyword_metrics or keyword_ideas, which an agent could easily confuse with it.

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 description only implies usage ('get difficulty scores for these keywords'). It never says when to choose this over keyword_metrics, keyword_ideas, or search_intent, nor when not to use it. No alternatives or exclusions are named.

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