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

With no annotations provided, the description carries the behavioral burden. It explicitly warns that 会创建真实账号 and states the tool returns a usable API Key, disclosing the key side effect. It doesn't cover duplicate-call consequences or reversibility, but the core behavioral risk is disclosed.

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 compact sentence that front-loads the main purpose, states the key side effect, and gives the usage condition. Every clause earns its place, and no extraneous information is present.

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?

For a tool with three string parameters and no output schema, the description covers purpose, return value, side effect, and usage timing. It lacks a detailed response format, but since it states that an API Key is returned, an agent can act reasonably without further detail.

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 the schema already describes email, password, and username. The description adds no parameter-specific detail beyond what the schema provides, so the baseline of 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 clearly states the tool's action: self-register an account, create an Agent, and return a usable API Key. This is a distinct resource and purpose that stands apart from siblings like ai_estimate, ai_request, get_onboarding, and list_assets, so an agent can easily identify what it is for.

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 explicitly marks the tool as optional and says 仅首次接入时使用, giving a clear condition of when to use it. It does not name alternative tools or describe when not to use it, but the first-use gate is concrete enough for an agent to choose this only during onboarding.

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