generations

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

With no annotations, the description carries full responsibility for behavioral disclosure. It details that list includes dates and current marker, NixOS entries include path when profile link exists, and rollback can target a specific generation or default to previous. This goes beyond a bare function statement.

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 description is concise and front-loaded, using a single paragraph with action-oriented sentences. Every sentence contributes meaningful information without redundancy or fluff.

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?

Given the tool's complexity and the existence of an output schema, the description covers the main use cases adequately. It explains both list and rollback behaviors and parameter options. However, it omits potential edge cases like error handling or destructive consequences, but the core functionality is well documented.

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. It thoroughly explains the meaning and usage of all three parameters: 'action' values, 'generation' as id/path, and 'mode' for home-manager. This fully clarifies the parameter semantics.

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 states the tool performs two specific actions: listing generations and rolling back to a previous generation. It provides distinct verbs and resources, distinguishing it from sibling tools like build, switch, and diff, which handle other operations.

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 description implies usage by defining the two actions and explaining when to use each (list to enumerate, rollback to revert). However, it does not explicitly compare to sibling tools or state when NOT to use this tool, leaving the selection guidance implicit.

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