check_set_coverage_tool

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

With no annotations provided, the description carries the full burden and does so well: it states 'Read-only, and touches no filesystem,' explains that `expected` is never inferred, and discloses the behavior for unexpected items ('deliberately earns no credit against the denominator'). This gives an agent a trustworthy model of side effects and result semantics.

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 front-loads the core purpose and usage, then uses later paragraphs for parameter semantics and output behavior. Each section earns its place; the examples are compact and collectively clarify the tool's scope without unnecessary fluff.

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 read-only, pure computational tool with an output schema and no side effects, the description is complete: it covers safety, parameter meanings, returned fields, and the special treatment of unexpected items. No critical information an agent would need to call it 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?

Schema description coverage is 0%, so the description must compensate, and it does for most parameters: `expected` is defined as the caller's declaration, `scope` names items for the sentence, `where` names where they were looked for, and `derivation` records how the expected set was arrived at. `found` is only implied as 'what was actually read' rather than explicitly named as the second required list, leaving a small gap.

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 precise verb-resource pairing: 'Check what a task required against what was actually read, over any two sets of keys.' It also distinguishes itself from dated-file-oriented siblings by saying 'when the thing you must account for is not dated files in a folder' and provides concrete example pairings, so an agent can tell this apart from related 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 context: 'Use this when the thing you must account for is not dated files in a folder,' followed by several illustrative scenarios such as documents vs. retrieved chunks and required controls vs. controls with evidence. It does not name alternatives or state explicit when-not-to-use cases, but the guidance is clear enough to route an agent correctly.

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