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

Annotations already establish readOnly, idempotent, non-destructive, but the description adds genuine behavioral context beyond them: the call does not repeat the write's effect, and a pending/unknown status must not be read as failure. That is useful, non-obvious operational guidance. It stops short of describing the receipt's fields or possible status values.

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?

Two tight sentences, no filler, with the core purpose front-loaded and the critical caveat (pending is not failure) following. Well sized for the tool's simplicity.

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 single-param read tool with rich annotations the description is largely sufficient, and it correctly focuses on interpretation rather than repeating safety hints. However, with no output schema it never describes what the receipt/status result contains, leaving the agent to discover the return shape at call time.

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% for the single operation_id parameter. The description's 'do not use a new operation ID' implies the ID must correspond to the original write, which adds some meaning, but it never documents the parameter directly. Baseline 3 is appropriate given the one self-descriptive parameter.

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?

States a specific verb (check) and resource (an uncertain write's durable receipt / operation status), so the agent understands this retrieves the outcome of a previously-issued operation. It does not explicitly name or contrast with the closest sibling (cairn_local_status), but the operation-receipt framing is distinctive enough to differentiate.

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?

Gives clear conditional guidance: use it when a write is 'uncertain', and it warns that a pending/unknown result is not proof of failure and that a new operation ID must not be used. This is strong when-to-use and how-to-interpret guidance, though it does not explicitly name alternatives.

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