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

Description mentions side effect of saving API key automatically, which is helpful. But with no annotations, it lacks disclosure of permissions, rate limits, error handling, or detailed behavior beyond creation.

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?

Three sentences, front-loaded with action and context, no redundant information. Every sentence serves a clear purpose.

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?

Provides essential usage context and side effect, but does not explain return value (though output schema exists) or detail billing parameters. Missing information for a complete understanding.

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 0%, and the description adds no meaning to individual parameters. It only implies name, email, password are required but doesn't explain what each parameter represents or the purpose of billing fields.

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?

Description clearly states 'Create a new AgentDomain account and save the API key,' specifying verb and resource. It also distinguishes from siblings like login by saying 'Call this first if you don't have an account.'

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?

Explicitly says to call this first if no account exists, giving clear context for when to use. However, it does not explicitly mention alternatives or when not to use, though the implication is clear.

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