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

With no annotations, the description carries the full burden and does so well: it discloses incremental storage (only the first copies the whole computer), a retention limit, that the machine keeps running uninterrupted, and that the state is read from the live filesystem so mid-write operations must be stopped first.

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 short paragraphs, front-loaded with the core definition before the when-to-use advice and caveats. Every paragraph is functional, though the 'let me start fresh' color is slightly decorative relative to the operational content.

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 mutating tool with no annotations, no output schema, and one well-documented parameter, the description is nearly complete — it covers intent, timing, incremental behavior, retention, and write-in-flight risk. It does not describe the return value, a minor gap given no output schema exists.

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 schema documents the single 'label' parameter, so the baseline is 3. The description adds meaning beyond it by prescribing a naming convention (name for what it is, e.g. 'before the schema change', not by number), which is genuinely useful guidance not present in 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?

Specific verb (save) plus resource (checkpoint) with an immediate definition of what a checkpoint captures — filesystem state and installed software, named and restorable. It is clearly distinguishable from restore_checkpoint and list_checkpoints by the direction of the operation.

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?

Explicitly enumerates when to take one (database migration, dependency/framework upgrade, large refactor, destructive script, handing off the machine) and frames the intended habit of checkpointing before every risky step. The alternative action, restoring, is implied by 'you can come back'.

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