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

With zero annotations the description must carry the entire behavioral burden. It does well on idempotency (header takes precedence, both must match) and on auth/storage ('only the hash is stored'), but says nothing about permanence, reversibility, or what a successful call yields — a notarization almost certainly returns a receipt or proof id, and that is never hinted at.

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 operation is front-loaded in the first clause and every sentence carries information. The dense semicolons, nested parentheses, and a trailing prompt-injection warning make it heavier to parse than necessary, though nothing is truly filler.

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?

Auth scope, idempotency, and storage footprint are covered, which is solid for a mutation tool with no annotations and no output schema. The missing pieces — the return value (proof/receipt), the role of 'label', and whether notarization is permanent — are things an agent would need before calling confidently.

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%, so the description must compensate for all three parameters. It explains idempotency_key thoroughly, including its header alternative and precedence rule, but 'label' is never explained — and the parenthetical 'only the hash is stored' actively raises doubt about whether label is persisted at all, leaving its purpose unclear.

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 opens with a specific verb+resource pair, 'Notarize a SHA-256 hash under my identity', so the operation is unambiguous. It does not differentiate itself from nearby siblings such as vault_proof, vault_head, or add_lineage, which an agent could plausibly confuse with a notarization step.

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 rather than stated: the agent learns it needs 'scope records' and that no request signature is required, which are real preconditions. However, there is no explicit when-to-use vs. when-not, and no pointer to which sibling to call instead for proof retrieval or verification.

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