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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds methodological context (baseline + variants) but does not describe return format, pagination, or any operational quirks. This is acceptable but not rich.

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 a single, front-loaded sentence with no filler. Every word contributes to conveying the tool's purpose and method. It is concise and well-structured.

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?

With no output schema, the description should explain what the tool returns (e.g., sensitivity metrics, verdict comparison). It only vaguely says 'measure verdict/score sensitivity' without specifying output structure. Given the complexity of six parameters and a specialized analysis purpose, more detail is needed for full contextual completeness.

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%, so all six parameters have clear descriptions. The tool description itself adds minimal parameter-level meaning, only hinting at the relationship between base_test and counterfactual_tests. This meets the baseline but does not exceed it.

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 states a specific action ('Run baseline plus counterfactual variants') and an outcome ('measure verdict/score sensitivity'), clearly conveying the tool's core function. However, it does not explicitly differentiate this tool from siblings like waveguard_compare or waveguard_mechanism_probe, though the 'counterfactual' term is fairly distinctive.

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 gives no explicit guidance on when to use this tool versus alternatives. It implies a use case (sensitivity testing) but does not state prerequisites, exclusions, or refer to sibling tools. There is no 'use when' or 'instead of' context.

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