fr_coverage

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

Annotations already include readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false. The description adds value by explaining the open-world nature explicitly ('the absence may be a gap in this connector rather than in the law') and by noting that 'Every gap carries a fallback saying where to look instead.' This provides behavioral context beyond the annotations without contradicting them.

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 well-structured and concise. It starts with the core purpose, then provides contextual usage guidance, and ends with return value details. Every sentence earns its place; there is no fluff or redundancy. The formatting with a returned section adds clarity.

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 that the tool has no parameters, rich annotations, and an output schema, the description adequately covers what an agent needs. It explains when to invoke the tool, what it returns (families, as-of note, known gaps), and the important caveat about fallbacks. There is no missing information that would affect correct invocation.

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 tool has zero parameters, so the description does not need to explain parameter semantics. According to the calibration, a baseline of 4 is appropriate for zero-parameter tools. The description focuses on purpose and behavior, which is sufficient.

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: 'Declare what this connector covers, how it is sourced, and what it does NOT cover.' It uses a specific verb ('Declare') and resource ('connector coverage'), and it is clearly distinct from sibling tools like fr_search or fr_get_act, which perform searches or retrievals. The purpose is unambiguous and easily distinguishable.

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 explicit when-to-use guidance: 'Call this before telling a user that the law 'does not contain' something, and whenever a search comes back empty.' This clearly indicates the appropriate context. However, it does not explicitly state when not to use it or name alternative tools, though it implies that searches should be done first. This is a minor gap.

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