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

Annotations already cover readOnly/idempotent/non-destructive, yet the description adds login requirement, that each prefill field requires explicit user confirmation, and that required fields cannot be skipped. These are real behavioral rules not derivable from the annotations or empty schema.

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?

Front-loads the login tag and purpose, then behavioral rules, then the workflow chain. Dense but every clause carries information; the combo-chain enumeration is arguably tangential to selecting this tool but still aids correct sequencing.

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 and no parameters, the description must carry the load, and it does: it names what is returned (missing items + prefill), the login precondition, the confirmation rule, and how it fits the onboarding pipeline. Only a brief note on the response shape is absent.

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?

The tool takes zero parameters, so the baseline is 4. The mention of bio/intro field semantics relates to returned data rather than inputs, so no additional parameter explanation is needed or expected.

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?

Starts with a concrete verb+resource: reads onboarding missing items (入驻缺项) and historical signup prefill data. An agent can tell this is a read-status tool, though it doesn't explicitly contrast itself against other read siblings like get_my_profile or get_signup_gaps, so it falls short of the top band.

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?

Gives real usage context: login required, and '先看completed避免重复' tells the agent to check this first before running the onboarding chain to avoid duplicating completed steps. It even enumerates the downstream tool chain, which is strong guidance, but it doesn't state when NOT to use this tool.

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