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

Annotations already declare readOnlyHint=true and destructiveHint=false; the description adds meaningful context on top by stating it "opens nothing by itself" and returns screens, buttons, and fields. The note that no public EZ Lawn Biller API exists explains why the browser-tool route is required, which is useful behavioral context an agent could not get from 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 purpose and the actual-vs-instructional distinction are front-loaded, which is good. The trailing API-research paragraph (404 URLs, FAQ referencing QuickBooks) is bulky for a tool description, though it does justify the browser-tool routing and prevent an agent from hunting for an API path.

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, the description carries the burden of describing the return value, and it does so concretely ("step by step (screens, buttons, fields)"). Combined with the zero-parameter schema and read-only annotations, an agent has enough to call it correctly, though the exact response format or size is not specified.

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 and there is nothing for the description to disambiguate. The description correctly implies no inputs are needed by framing the call as a pure guidance lookup.

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 and resource ("Run Payroll in the user's own EZ Lawn Biller account") and immediately disambiguates that it returns step-by-step instructions rather than executing anything. It does not differentiate itself from close siblings such as ez_lawn_biller_finalize_payroll or ez_lawn_biller_review_payroll, so an agent must infer which payroll stage this guide covers.

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?

It gives a clear follow-on path — do the actual work with the cotlet_browser_* tools in the Cloud Browser — which is real usage guidance. However, there is no statement of when to pick this over review_payroll, finalize_payroll, or historical_payroll, and no explicit when-not conditions, so routing among payroll siblings 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.