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

Annotations already declare readOnly, idempotent, and non-destructive. The description adds behavioral nuance beyond these annotations: it returns z-scores against a catalogue population, generates a characterisation from extreme descriptors, and outputs nearest neighbours. This explains the analytical nature of the tool without contradicting the safety hints.

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 three sentences: the first lists outputs, the second contrasts with a sibling, the third gives usage timing. Every sentence carries essential information, and the core purpose is front-loaded. No filler or redundancy.

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?

Given the tool's moderate complexity (multiple output components) and the presence of an output schema, the description adequately covers purpose, usage, and output behavior. It also clarifies the relationship to sibling tools, so the agent has full context to decide when to invoke it.

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 parameter description includes a concrete example and tells how to discover valid values. The tool description itself doesn't add much beyond what the schema provides, but it doesn't need to since the schema is already explicit. Baseline 3 is appropriate.

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 'Single-regime introspection' and enumerates concrete outputs (median behavioural descriptors, z-scores, English characterisation, nearest neighbours), making the tool's function unmistakable. It also explicitly contrasts with the sibling find_similar_regime, clarifying what this tool uniquely does.

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 direct usage guidance: 'Read this before searching if you want to reason about one regime first.' It explicitly names the alternative tool and explains the difference in behavior, so the agent knows when to choose this tool over find_similar_regime.

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