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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false, so the safety profile is covered structurally. The description adds real context beyond that: it is a 'signed statement' and a head-relative snapshot, and the final sentence implies the result is meant to be checked for omissions. It stops short of return format, pagination, or auth expectations.

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 sentences, no padding, with the core object ('signed statement of one completeness chain') front-loaded. The second sentence is metaphorical rather than operational, which costs a bit of efficiency but still carries meaning.

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?

With no output schema, the description properly takes on the burden of describing the return payload: chain length plus per-position leaf, time, and digest. That is unusually complete for a read tool, though it leaves range/pagination behavior of from/to to inference.

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 coverage is 100%, so chain_tag, from, and to are already documented in the schema; baseline 3 applies. The description's 'for each position' phrasing loosely corroborates the from/to range semantics but adds no syntax or edge-case detail beyond what the schema states.

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 names a specific resource (one completeness chain) and enumerates what it returns: length plus per-position leaf, time, and digest. The phrase 'as of the current head' pins the scope well, but it never distinguishes itself from close siblings like get_consistency_proof or get_inclusion_proof, which an agent would need to route between.

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?

There is no explicit when-to-use statement, no exclusions, and no named alternative among the six sibling 'get_*' tools. The closing line ('A position nobody showed you is a record left out') gestures at significance but is an interpretive remark, not usage guidance.

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