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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds value beyond them by specifying the exact return structure, the meaning of each contributor field ('the name shown and human or agent'), and the empty-array behavior when no version exists. It stops short of noting ordering guarantees or size/pagination characteristics, which is a minor residual gap for a list tool.

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?

Two sentences, front-loaded with the action and return shape, with the structural detail ({ index, timestamp, contributors }) inline rather than padded. Every clause carries information; nothing is redundant with the title.

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 takes on the burden of explaining returns and does so fully: array element shape, nested contributor shape, and the empty-array case. Combined with annotations covering safety and a fully documented single parameter, an agent has everything needed to call this correctly.

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?

There is a single parameter with 100% schema description coverage ('Document ID'), so the schema already carries the semantics. The description implies the ID identifies the document whose history is listed but adds no format, source, or lookup guidance beyond that, so baseline 3 applies.

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 verb and resource ('Lists an ODocs.co document's saved versions') and immediately pins down the return shape as an array of { index, timestamp, contributors }. It also distinguishes itself from get-version, which handles version content, so an agent can tell the two apart without opening either schema.

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?

The last sentence explicitly routes the agent: this tool gives indices, and get-version returns content 'for its index.' That is clear context and a named alternative, though there is no explicit when-not-to-use statement (e.g., for documents with no history the empty-array case is described but no alternative is offered).

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