verify_fact

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

With no annotations provided, the description carries the full behavioral burden. It explicitly discloses a non-obvious trait: 'No boolean verdict — entailment is the caller's job,' which prevents the agent from expecting a yes/no answer. This is meaningful behavioral context beyond the schema, though it does not discuss safety or permissions.

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 compact and well-organized: a one-line purpose, a 'USE WHEN' trigger, and a crucial behavioral caveat. Every sentence earns its place and the most important scoping information is front-loaded.

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 two-parameter retrieval tool with an output schema, the description covers purpose, usage context, and the key behavioral boundary. It does not explicitly route between sibling tools, but the name and 'USE WHEN' clause make the intended use reasonably complete.

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 0%, so the description must compensate. It clarifies that 'statement' is the claim to verify against the graph, adding meaning beyond the schema. However, 'limit' receives no explanation, though its default of 5 and name make its basic meaning inferable.

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 uses a specific verb and resource: 'Retrieve knowledge-graph evidence relevant to a statement.' It clearly frames the tool as a fact-checking/evidence-gathering operation, distinguishing it from generic search siblings by emphasizing that the caller, not the tool, judges entailment.

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 'USE WHEN' clause explicitly states when to invoke the tool: 'You want to check a claim against the graph.' It provides clear context and sets expectations about no boolean verdict, but it does not name sibling alternatives or state when not to use them, so it falls short of a 5.

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