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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered and the bar is lower. The description adds real substance by naming the answer's contents, including the grant snapshot concept, but it never says what happens when 'version' is omitted (default null) — latest version, error, or explicit miss — which is significant behavioral information for a point-in-time attribution lookup.

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 tightly packed sentence that front-loads the answer the tool produces and uses the parenthetical '(the grant snapshot)' to compress a concept efficiently. No filler, though the sentence is dense enough that the three returned facts arrive without hierarchy.

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?

An output schema exists, so explaining return values is unnecessary, and the tool is a simple two-parameter read. The remaining omissions — the ref format and the behavior when version is null/absent — are exactly the things an agent needs to invoke it correctly, so the definition is adequate but not complete.

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 carry the parameter burden. It does tie 'version' to a document version and implicitly ties 'ref' to a document reference, which is meaningful, but it gives no expected format for 'ref' (path, id, namespace-qualified name) and does not explain the null/default semantics of 'version', leaving a material gap.

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 states a specific investigative purpose: attribute a document write to an author, the token issuer, and the grant snapshot in force at write time. 'Answer who wrote a document version' is a clear verb+resource framing that lets an agent distinguish it from generic audit or lineage readers. It stops short of explicitly naming a sibling it is not (e.g. get_lineage, get_audit_view).

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 when-to-use or when-not-to-use guidance and no named alternative, despite several siblings covering adjacent ground (get_lineage, get_lineage_attestation, get_audit_view, get_token, list_token_tree). The phrase 'at write time' hints at a point-in-time attribution use case, but an agent must infer the routing decision entirely on its own.

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