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

The annotation already declares readOnlyHint=true, and the description adds that the tool shows added, removed, and modified rules. This is useful but modest context; it does not disclose limits, ordering, pagination, or how snapshots are sourced. With annotations lowering the bar, 3 is appropriate.

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 two short sentences that lead with the primary action and output, then give the use case. There is no filler or redundancy; every word contributes.

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?

Required parameters are fully documented, the read-only safety is covered by annotations, and the description states the output scope in terms of added/removed/modified rules. Given the tool's moderate complexity, this is nearly complete; only minor expectations about the diff format or prerequisites are not specified.

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 100% and the base/target parameter descriptions already explain their meaning. The tool description adds no additional parameter-level semantics beyond what the schema provides, so the baseline of 3 is justified.

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 a specific action — comparing rule snapshots between two versions — and names the output categories (added, removed, modified). This strongly distinguishes the tool from other deployment and comparison siblings, and the verb 'compare' precisely names the behavior.

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 phrase 'Useful for reviewing changes before deploying a new version' gives clear usage context and position in the deployment workflow. It does not explicitly exclude alternatives or mention sibling tools, but the context is sufficient for an agent to know when this tool is appropriate.

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