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

Annotations already establish that this is not read-only, destructive, or idempotent. The description adds useful behavioral context beyond those annotations by specifying that the response is a K01-style id and by clarifying that the due date is counted from the hire's start date. It does not contradict the annotations.

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 two sentences with no filler. The first sentence states the action and return value, and the second clarifies date counting. It earns its place without duplicating schema details unnecessarily.

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?

All four required parameters are documented in the schema, and since there is no output schema, the description supplies the missing return contract. For a simple create tool, this is complete enough for an agent to call it correctly.

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%, with each parameter fully described including the owner enum and due_offset semantics. The description mostly restates the due_offset behavior rather than adding new parameter-level meaning, so the baseline score 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 states a specific verb ('Add'), a specific resource ('a hire's plan'), and the expected result ('return its K01-style id'), while listing the key attributes involved. This clearly separates it from siblings like onboarding_task_done and onboarding_template_apply, which operate in the same domain but perform different actions.

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?

There is no explicit guidance about when to use this tool versus alternatives, such as 'use this for individual task creation rather than applying a template'. The phrase 'Add one task' and the sibling tool names imply the intended use, but the agent must make that inference rather than being told.

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