check_difficulty

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

No annotations are provided, so the description carries full burden. It only mentions the API key requirement but does not disclose read-only nature, rate limits, or what 'SERP analysis' entails. For a tool with no annotations, this is insufficient.

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 description is a single sentence that efficiently conveys the core purpose and a key requirement. It is front-loaded and concise, though it could be slightly reorganized to separate behavioral info from purpose.

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 annotations and missing usage guidelines, the description is not fully complete. It covers the basics but lacks details on when to use, behavioral traits, and potential limitations. The presence of an output schema mitigates the need to describe returns.

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 input schema has 100% coverage, describing both parameters (keyword and country). The description adds no additional meaning beyond the schema, so 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?

The description clearly states the tool checks keyword difficulty and returns SERP analysis, using a specific verb and resource. It distinguishes from sibling tools like keyword_ideas or onpage_audit by focusing on difficulty and SERP data.

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 mentions a prerequisite (CAPSOLVER_API_KEY) but does not specify when to use this tool versus alternatives like keyword_ideas or onpage_audit. There is no guidance on when not to use it or context for selection among siblings.

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