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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is covered. The description adds real semantic context beyond them: what the returned proof actually guarantees (prefix/append-only consistency) and that omitting 'second' falls back to the current tree ('or now'). It stops short of noting any response format or verification steps.

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?

A single compact sentence, front-loaded with the guarantee and followed by the plain-language meaning after the colon. Nothing is wasted, though the unquoted parameter names ('size first', 'size second') read slightly awkwardly inside an otherwise tight statement.

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 carries more of the return-value burden, yet it never says what form the proof takes or how it is consumed (e.g., verified against checkpoints or evidence heads). For a low-parameter cryptographic read tool it is adequate but leaves the agent guessing about the deliverable.

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 baseline is 3, but the description goes further by relating the two parameters to each other ('tree at size first is a prefix of the tree at size second') and documenting the default behavior of the optional 'second' via '(or now)', which the schema description ('a later tree size') does not convey.

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 artifact (a consistency proof) and exactly what it asserts: the tree at size 'first' is a prefix of the tree at size 'second'. That is a clear verb+resource equivalent for a proof-generation tool. It does not, however, contrast itself with closely related siblings such as get_inclusion_proof or get_checkpoint, so an agent must infer the distinction.

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 or when-not-to-use guidance. The clause 'the log never rewrote history' hints at the verification intent, but the description never names the sibling alternative (get_inclusion_proof for leaf inclusion, get_checkpoint/get_evidence_head for heads), so routing between these near-identical read tools is left to inference.

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