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

With no annotations, the description must carry the burden of disclosing behavior. It fails to state whether the tool returns a numerical constant, accepts no input, or performs any side effects. 'Constant decay' conveys no operational detail.

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 description is very short, but brevity here is under-specification, not conciseness. It repeats the name in slightly diffrent words and provides no useful content for an agent.

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?

The tool has no params, no output schema, and no annotations, so the description is the sole source of guidance. It does not explain what value is returned, in what units, or how the result is obtained. An agent cannot predict the tool's behavior at all.

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 input schema has zero parameters, so there are no parameter semantics to clarify. The baseline for 0 params is 4; the description does not need to document parameter meanings.

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 'Decay Constant: Constant decay' is a tautology – it restates the tool name without explaining what the tool does, what it computes, or what output it produces. It cannot be distinguished from related siblings like x402-radioactive-decay or x402-half-life.

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 zero guidance on when to use this tool instead of any sibling. It never mentions alternatives, prerequisites, or context such as radioactive decay or half-life calculations.

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