Verify our published total and our statement log (skeptical client)

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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so safety is covered structurally. The description adds real behavioral context beyond that: what the verification actually checks (Merkle-sum root, leaf-to-root proof, unchanged/changed/removed/added counts, consistency proof), and the operational requirement to retain and re-pass the returned heads. It omits auth/permission or failure-mode behavior, so it is not a 5.

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 content mostly earns its place, but it is delivered as a long run-on sentence with the actual purpose buried behind a rhetorical opener ('Trust nothing you did not recompute'), so it is not front-loaded on the verb. Dense but not padded; structure is the weak point.

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?

There is no output schema, so the description must carry the return semantics, and it does: it states that it reports unchanged/changed/removed/added leaf counts, returns heads to keep, and verifies consistency. Combined with full schema coverage on the three optional inputs, an agent has enough to call and chain it, though it says nothing about error/failure reporting.

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 the baseline is 3, but the description adds genuine meaning: it explains that 'agent' triggers climbing that agent's proof from leaf to root, that previous_head is 'the sum-log head you kept', and that previous_statement_head drives the consistency proof that history was not rewritten. That ties the nested objects to concrete cryptographic purposes rather than restating field names.

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 concrete verb and resources: it verifies the Ed25519 signature on the sum-log head, optionally climbs an agent's Merkle proof, diffs leaves against the previous head, and verifies the statement log's signed tree head and consistency proof. That is far more specific than a tautology and lets an agent distinguish it from siblings like agent_statement or since_last. It stops short of explicitly naming the sibling tools it supersedes, so it is not a 5.

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?

Usage is implied by the title's '(skeptical client)' framing and by 'optionally climbs one agent's proof' plus 'Keep the heads it returns and pass them next time,' which tells the agent how to chain calls. However, there is no explicit when-to-use vs when-not statement and no named alternative among the sibling tools, so guidance remains inferred rather than stated.

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