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

Annotations already declare readOnly, idempotent, openWorld, and non-destructive, so safety is covered. The description adds genuinely new behavioral context: a $0.001 USDC x402 payment requirement and an alternate HTTPS endpoint, plus an implicit failure condition for improper fractions. The return type (an integer count) is only implied, not stated.

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?

Front-loaded with the definition, then examples, then constraints, then pricing/endpoint — a logical order with little waste. Four examples are slightly more than strictly needed, but each is short and illustrative.

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-integer, no-output-schema tool, the description supplies the computation, examples, input domain, properness requirement, and payment/transport details. The only gaps are an explicit statement of the return type and behavior on invalid (improper) input.

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 coverage is 0%, so the description must carry parameter meaning. It states the ranges (a: 1–30, b: ≥2) and that the fraction must be proper (implying a<b), which partly compensates. It never explicitly labels a as numerator and b as denominator, so the mapping remains inferred.

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 states a specific computable quantity — the count of unit fractions in the greedy Egyptian expansion of a/b — and four worked examples (1/2→1, 8/11→4) make the operation unambiguous. It does not explicitly distinguish itself from sibling tools like egypt_greedy, egyptian_first, or egyptian_sum, which prevents 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?

No guidance on when to pick this tool versus the many Egyptian-fraction siblings (egypt_greedy, egypt_check, egyptian_sum, etc.). The stated domain constraints (proper fraction, 1–30) describe valid input rather than when-to-use context.

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