Roll back a data file

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

Annotations already declare destructiveHint=true and idempotentHint=false, so the safety profile is covered structurally. The description goes beyond that by disclosing the backup-selection logic (newest vs one-before-when-disk-matches) and the 0=oldest ordering, but it never states that the current file content is overwritten or what happens on failure.

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?

Three sentences, front-loaded with the core action, then the identifier format, then the `to` behavior, then the routing hint. Every clause carries information and none restates structured fields redundantly.

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 simple two-parameter destructive tool with annotations carrying the safety profile and no output schema, the description covers purpose, identifier formats, parameter branching, ordering, and the sibling alternative. Nothing an agent needs to call it correctly is missing.

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 only 50%, with `table` undocumented in the schema, yet the description fully compensates by enumerating the accepted identifier forms (database name, map as Map037/37, project-relative path) with concrete examples. It also restates the `to` semantics (backup number, 0=oldest, omit for newest) meaningfully.

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 opens with a specific verb+resource ('Restore a backed-up copy of one file') and explicitly contrasts itself with siblings by referencing list_backups for identifiers and undo_writes for multi-file undo. An agent can disambiguate rollback_data from undo_writes 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?

It spells out the when-to-use branching: without `to` it reverts the newest change, with `to` it restores a specific backup, and it names the alternative ('prefer `undo_writes`') with the condition that selects it. This is explicit when/when-not/alternatives guidance.

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