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

With no annotations at all, the description carries the full behavioral burden and largely fails it: it never says whether the result is a percentage or decimal, whether inputs are numbers-as-strings, or what happens on zero net income. The one genuine disclosure is commercial/behavioral — five free trial calls per signed wallet — which is useful but unrelated to how the computation behaves.

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?

It is very short and front-loaded, which is good, but half the text is a circular restatement and the other half is promotional boilerplate. Being terse here reflects under-specification rather than disciplined editing.

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 a two-input calculation with no output schema and no annotations, the description should define the formula, input format, and result shape; it defines none of them. An agent could call it, but only by guessing at semantics and it would not know how to interpret the response.

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?

Both parameters are undocumented in the schema (0% coverage) and the description adds nothing about dividends or netIncome, so the agent must infer from financial convention that dividends are subtracted from net income. The mapping is guessable from the metric name, which keeps this from the floor, but no format, unit, or requiredness guidance is provided (required count is 0).

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 gloss "Ratio of retention" simply restates the tool name, which is a textbook tautology. An agent learns that this is some financial retention metric but not what it computes (retained earnings divided by net income) or how it differs from near-identical siblings like x402-dividend-payout-ratio or x402-plowback-ratio.

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 when-to-use guidance, no mention of the alternative complementary ratio tools, and no preconditions beyond the pricing note. The only additional sentence concerns free trial calls and a signed wallet, which is billing context rather than usage direction.

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