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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds useful behavioral context: the tool returns constraints rather than variants themselves, and it encodes the 'one idea per slot' rule. It does not discuss auth or rate limits, but the annotations cover the safety profile.

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 four sentences, front-loaded with the core function, then the single most important constraint, and then the correct call timing. Every sentence earns its place with 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?

With an output schema present, annotations covering safety, and a description that states the key design rule and workflow position, the tool is well covered. Minor gaps are the unexplained 'slot' concept and the vague phrase 'whether a test can be read at all,' but these do not block correct invocation.

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 60%, and the existing descriptions for goal, format, and audience carry most of the parameter meaning; count has explicit min/max/default and channel has an enum. The description adds no parameter-specific detail beyond mentioning email/web, so it does not compensate for the two undocumented parameters or add new semantic value.

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 the tool's function: it 'Returns the constraints to write or generate test variants against, for email or web' and also mentions rules for whether a test can be read. This distinguishes it from siblings like build_test or register_test by role, though it never names a sibling explicitly.

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?

It gives explicit workflow placement: 'Ask for this before drafting variants, then produce them yourself against what it returns.' This tells the agent when to call it, but it does not mention when not to call it or point to alternative tools.

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