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

Annotations already declare readOnlyHint=false, idempotentHint=false, and destructiveHint=false, so the safety profile is covered. The description adds genuinely new behavioral context: the gating condition on required steps and the recommendation to pre-verify state. It does not disclose what happens if the tool is called when prerequisites are unmet or when onboarding is already complete, which keeps it below 5.

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 short sentences with no filler; the state change is front-loaded, followed by the gate condition and the timing cue. Every sentence carries operational information.

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 zero-parameter, non-idempotent state-transition tool with no output schema, the description covers what to do before (verify status), when (end of conversation), and the precondition. What is missing is the failure/already-complete behavior, which matters for a non-idempotent call.

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?

Zero parameters are defined and schema description coverage is 100%, so the baseline of 4 applies. There is no parameter information for the description to add or omit.

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?

States a specific verb+resource: 'Mark the user's onboarding as complete.' This tells the agent exactly what state change occurs. It falls short of 5 because the sibling set contains several other onboarding-completion tools (finish_agent_onboarding, onboarding_v7, log_agent_onboarding) that are not distinguished from this one.

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?

Explicit prerequisites ('Only works once all required steps (payment + required social connection) are done'), an explicit verification step ('verify with get_onboarding_status first'), and an explicit triggering moment ('at the end of a successful onboarding conversation'). Nothing is left to inference.

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