List Undo History

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

Annotations already indicate read-only, idempotent, and non-destructive behavior. The description adds valuable context beyond annotations: it reads a local journal file, never the YNAB API, returns most recent first, and explains the meaning of undoable:false. This is transparent and consistent with the annotations.

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?

Four sentences with no wasted words. The core purpose and ordering are front-loaded, followed by the read-only distinction, usage guidance, and the undoable:false caveat. Every sentence contributes necessary information.

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 single-parameter read-only tool with a rich description, an output schema, and safety annotations, this is complete. The description covers behavior, source, ordering, use cases, and a key edge condition; return format is covered by the output schema.

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 the only parameter, limit, already has a full description including default and maximum. The tool description doesn't add further parameter semantics, so the baseline 3 applies given the schema handles the documentation burden.

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: 'List the local undo journal' with clear scope ('every write this MCP server performed'). It distinguishes itself from YNAB API tools by explicitly saying it reads a local journal file and never the YNAB API, making sibling differentiation unambiguous.

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?

Provides explicit use cases: review before calling undo_operation, or audit a session's writes. It also clarifies the limitation that entries with undoable:false are only for audit and cannot be reversed, giving agents actionable guidance on when the tool is useful.

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