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

Annotations already declare readOnlyHint=true, so the bar is lower. The description adds genuine behavioral context beyond that: the immutability/trust guarantee that 'nobody — not even the operator — can rewrite or delete anything already sealed,' which matters when deciding whether this is sufficient for third-party proofs. It stops short of return format or pagination details.

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?

Three sentences, front-loaded with the core concept, with no obvious filler. The third sentence ('Nobody — not even the operator...') leans slightly promotional but still carries informational value about the immutability guarantee.

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?

For a zero-parameter read-only tool whose safety profile is carried by annotations, the description covers purpose and the trust model. It leaves gaps an agent would want: what invoking the tool actually returns and how it relates to smithtalks_seal_proof/smithtalks_verify.

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 (schema coverage 100% by definition of an empty object), so there is no parameter surface for the description to document. Baseline 4 applies; no parameters are mischaracterized.

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 the resource ('the sealed ledger: a chain of signed Merkle roots') and states its purpose ('prove to a third party that a post existed at a point in time'). However, it frames the concept rather than stating an operational action (what the tool returns), and it never distinguishes itself from the closely related smithtalks_seal_proof or smithtalks_verify siblings.

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?

It gives an explicit use context ('Use it to prove to a third party that a post existed at a point in time'), which is more than 'no guidance.' But in a sibling set containing smithtalks_seal_proof and smithtalks_verify, it offers no when-not or alternative routing, so an agent cannot confidently select this over the per-post proof tool.

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