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

Annotations already declare readOnly/idempotent/non-destructive, and the description adds genuinely new behavioral context: it returns a link, files are generated in the browser, crew data travels in a URL fragment never sent to the server, and SSN digits are entered only client-side. This is exactly the extra context structured fields cannot convey.

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-loaded with the trigger, followed by return behavior and the privacy constraint in tight sentences. No sentence is redundant with the schema or annotations, and every one carries actionable 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?

Despite a complex two-parameter schema with deep nesting, the description plus an existing output schema cover the essentials: when to invoke, what is computed, what is returned, the privacy model, and the size limit. Nothing an agent needs to call it correctly is missing.

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 coverage is 100%, so the schema baseline is 3. The description adds parameter-level constraints not in the schema — do not include SSNs or addresses in the arguments, and the 50-worker cap — which meaningfully shapes how the two top-level arguments are populated.

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?

Specific verb (build/produce) + resource (weekly WH-347 certified payroll) with the output format named (PDF or Excel). It is clearly distinguishable from siblings like check_crew_pay or reconcile_fringe_6b, which validate rather than build the export.

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?

"Use when the user is ready to produce the weekly certified payroll" gives a clear trigger condition, and "Do not put SSNs or addresses in the arguments" is a concrete precondition. It does not name alternative sibling tools or state when *not* to use it, so it stops short of a 5.

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