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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered and the description only needs to add context. It contributes that the tool is free and computes to the cent, but with no output schema present it should describe the shape of the returned breakdown and does not. It also says nothing about the cap interaction behavior when cap_paid_so_far exceeds cap_cents.

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?

Two sentences, front-loaded with the purpose before the input requirements, and no filler. The second sentence is long but each clause maps to a distinct parameter group, so it earns its length.

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 an eight-parameter tool with zero required parameters, the description never explains what happens if the caller supplies nothing, nor which combinations are valid (gci versus sale_price plus commission_pct). With no output schema, the return value is only loosely gestured at as 'to the cent'. Adequate but with clear gaps for a calculation tool of this complexity.

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 all eight parameters, including the cents units and the 'agent first' split ordering. The description restates the parameter set in prose ('split (like 70/30, agent first), an annual cap, how much of the cap is already paid, a per-deal fee and a referral percent') without adding constraints such as valid split formats or behavior when split sums to something other than 100. This is the expected baseline when the 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 names a specific verb and resource — a commission calculator computing what the agent and brokerage each receive from a closed deal — which is far more concrete than the title alone. It does not distinguish itself from the sibling 'commission_preview', leaving the agent to infer the difference between the two, so it stops short of a 5.

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?

Usage is implied rather than stated: the description tells the caller to 'Give the sale price and commission percent (or the gross commission in dollars)', which frames the two input modes but never says when to choose this tool over commission_preview or record_deal. There are no explicit when-not conditions or prerequisite notes.

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