ch_coverage

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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint false. The description adds valuable context by explaining the open-world semantics: an empty search result may reflect a connector gap rather than the law, and each gap includes a fallback. This reinforces and operationalizes 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 concise and well-structured: purpose first, usage trigger second, return value last. Every sentence earns its place, with no redundant filler. The critical warning about empty search results is front-loaded and easy to act on.

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 zero-parameter, read-only tool with rich annotations and an output schema, the description is fully sufficient. It explains what the tool covers, when to call it, why it matters, and what it returns. Nothing an agent needs to decide to invoke this tool correctly is missing.

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 schema is trivially complete. The baseline for zero-parameter tools is 4, and the description adds no parameter-specific information because none is needed. It appropriately focuses on behavior and return value instead.

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 opens with a specific declarative statement of what the tool does: 'Declare what this connector covers, how it is sourced, and what it does NOT cover.' It also specifies the return type ('Coverage with families, an as-of note, and a non-empty list of known gaps'), making the tool's role distinct from the sibling ch_search_acts and ch_get_act tools.

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 gives explicit usage triggers: 'Call this before telling a user that the law "does not contain" something, and whenever a search comes back empty.' It explains the rationale and even notes that gaps carry fallbacks. However, it does not name the sibling tools as alternatives or explicitly state when not to use it, so it stops short of a full 5.

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