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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the agent knows this is a safe read operation. The description adds the 'by Id' scoping constraint, which is useful. However, it doesn't disclose behavior like 404 handling, whether the employee must be active, or response shape. With annotations covering the safety profile, a 3 is appropriate – the description adds some value but not rich behavioral context.

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?

One sentence with zero waste. The core action, resource, system, and lookup key are all front-loaded. Every word earns its place.

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?

Complete for a simple read-by-id tool whose annotations already carry the safety profile. The only minor gap is not explicitly routing to search_employees when an Id is unavailable, but the schema and sibling list make that inferable. No output schema exists, but for a single-entity getter the return value is self-evident.

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 documents both parameters. The description adds 'by Id' which reinforces the id parameter's role, but doesn't add meaning beyond what the schema provides. Baseline 3 is correct when schema does the heavy lifting.

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 ('Get'), a specific resource ('a single employee'), and the system ('QuickBooks Online'), and identifies the lookup key ('by Id'). It is clear and distinguishes from search_employees (which searches) and create_employee/update_employee (which mutate). It doesn't explicitly name a sibling, but the verb+resource+scope is enough to differentiate.

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 implies usage: use this when you have an employee Id and need a single employee record. It does not explicitly state when to use search_employees instead (e.g., when you don't have an Id or need multiple employees), nor does it mention that the company parameter is optional when only one company is connected. The schema covers the company parameter, but the description provides no explicit routing guidance.

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