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

With no annotations provided, the description carries the full burden of behavioral disclosure. It describes key traits like using real-time web search, the impact of URL restrictions (grounding may fail if URLs lack info), and the option to bypass cache. However, it omits details such as rate limits, authentication needs, or specific error handling, leaving some behavioral aspects unclear.

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 appropriately sized and front-loaded, starting with the core purpose. Both sentences earn their place by adding useful context about URL handling, though it could be slightly more streamlined by avoiding minor redundancy with the schema (e.g., repeating URL accessibility advice).

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?

Given the tool's complexity (fact-checking with web search) and no annotations or output schema, the description is moderately complete. It covers the main purpose and parameter usage but lacks details on output format, error cases, or performance expectations, which are important for an agent to use it effectively without structured output guidance.

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 all parameters thoroughly. The description adds minimal value beyond the schema by reiterating guidance on the references parameter (e.g., ensuring URLs are accessible and relevant), but it doesn't provide additional semantic context or examples not covered in the schema, warranting a baseline score.

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's purpose with a specific verb ('ground') and resource ('statement'), explaining it uses real-time web search to check factuality. It distinguishes the action from generic search by specifying the grounding objective, and with no sibling tools, this level of specificity is excellent.

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 provides clear context on when to use the tool (for fact-checking statements) and includes guidance on the references parameter (e.g., ensure URLs are publicly accessible and relevant, or omit to search the entire web). However, it lacks explicit alternatives or exclusions, as there are no sibling tools, so it doesn't fully address when-not-to-use scenarios.

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