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 without the description. The description contributes the fact that the returned hash is cryptographically signed and covers 'recorded quotes', which is meaningful extra context, but says nothing about auth requirements or whether the value changes over time.

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?

One short sentence with no filler, and the key qualifier ('signed head hash') is front-loaded. It is terse to the point of being a fragment rather than a sentence, but nothing in it is wasted.

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 parameters, no output schema and full annotation coverage, the bar is low, and the description does identify the returned artifact. It still omits any indication of what an agent does with the attestation or how it relates to the sibling proof tools, leaving the integration story incomplete.

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?

The tool takes zero parameters, so there is no parameter semantics to explain; the baseline for a no-arg tool is 4. Nothing in the description contradicts or muddies the empty schema.

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 — the signed head hash of the hash-chained audit ledger — which distinguishes it from get_chain and get_checkpoint. However it is a bare noun phrase with no verb, so it reads as a label for the payload rather than an action the agent performs. Purpose is inferable but not stated crisply.

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 guidance on when to call this versus the closely related siblings (get_evidence_head, get_checkpoint, get_consistency_proof). The agent must guess whether an attestation is a prerequisite for verification flows or a standalone audit artifact.

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