nexus_snapshot

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

The description states that the tool 'creates a restore point with full file contents', which implies a persistent side effect (writing snapshot data). However, the annotations declare readOnlyHint=true, indicating no state mutation, creating a direct contradiction between the description and the safety profile. This is a serious inconsistency that could lead an agent to wrongly assume the operation is side-effect-free.

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 very concise: two sentences, no filler, with the main verb and purpose stated first. It front-loads the key action and provides a brief elaboration on what the snapshot contains, earning full marks.

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?

The description is adequate for a simple checkpoint tool but fails to resolve the contradiction with annotations, and it omits details about idempotency behavior or how the restore point is stored. Since the readOnlyHint misleadingly suggests no side effects while the description creates one, the contextual picture is inconsistent and incomplete.

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?

The input schema already provides descriptions for both parameters (id and files), giving 100% coverage. The description does not add additional semantics beyond saying 'full file contents', which aligns with the schema's 'files' description. Thus the description adds minimal value beyond the schema, meriting the baseline 3.

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 uses specific verbs ('Checkpoint', 'Creates a restore point') and a clear resource ('files'), and it distinguishes the tool from siblings like nexus_restore by explicitly stating it snapshots file contents. The phrase 'before editing' clarifies its role as a pre-edit safety measure, making the purpose 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?

The description provides an explicit usage context ('before editing') that tells the agent when to invoke this tool, differentiating it from restoration workflows. It does not enumerate exclusions or alternative tools, but the timing guidance is clear enough to guide selection.

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