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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false. The description adds meaningful behavior beyond those annotations: invalid fractions are rejected, calls cost $0.001 USDC on successful x402/Solana invocation, and an HTTPS endpoint is available. It does not detail the exact return structure, but the example partially compensates.

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 front-loaded with the core definition and example, then adds validation, pricing, and endpoint information. Most sentences earn their place, though the HTTPS endpoint line is supplementary rather than essential for tool selection.

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 simple two-parameter mathematical tool with no output schema and safety annotations already present, the description is largely complete: it defines the domain, gives an output example, states rejection behavior, and notes payment. Minor omissions remain around exact return type and parameter bounds.

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 0%, so the description must carry parameter meaning. It explains that a/b forms the fraction and that the fraction must be strictly between 0 and 1, implying a is the numerator and b the denominator. It does not explain the 0–5000 bounds or explicitly label numerator and denominator, leaving some gaps.

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 clearly states the operation: computing the greedy Egyptian fraction expansion for a proper positive fraction a/b. The example 5/6 = 1/2 + 1/3 makes the output concept concrete, though it does not explicitly differentiate this tool from sibling Egyptian-fraction tools such as egyptian_length or egyptian_sum.

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 specifies a validity condition — the fraction must be strictly between 0 and 1 or it is rejected — which tells the agent when not to use the tool. However, it gives no guidance on when to prefer this tool over sibling tools like egyptian, egypt_check, or egyptian_sum.

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