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

The readOnlyHint annotation already establishes that this is a safe read. The description adds two things beyond that: the ordering guarantee ('newest first') and the identification of isCurrent, which the schema does not express. However, it repeats return fields that the output schema already documents and says nothing about limits, pagination, or how many versions a block retains.

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 compact sentence, front-loaded with the resource and the ordering. The field enumeration slightly duplicates the output schema, which is the only waste, but the phrasing is efficient overall.

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 one fully documented parameter and an output schema present, the description does not need to explain return values, and it correctly does not attempt to. The main missing piece is operational guidance: whether versions are paginated or bounded, and how this tool pairs with rollback-version and submit-version.

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 coverage is 100% and blockId is described as a 'WordPress block id from list-blocks', so the schema already carries the parameter semantics. The description only implies that blockId selects the block whose versions are listed, adding no format or constraint detail beyond the 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 clearly identifies the resource (a block's saved versions), and the title supplies the verb 'List'. It also implicitly distinguishes itself from rollback-version by naming versionId as the input that tool expects. It stops short of an explicit verb+scope statement in the description itself.

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 explicit when-to-use or when-not-to-use guidance. The parenthetical 'versionId for rollback-version' implies the intended workflow (inspect versions, then roll back), but the agent has to infer that the tool is a prerequisite for rollback-version rather than being told so.

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