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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so safety is covered. The description adds meaningful behavioral context beyond annotations: the $0.001 USDC price per successful call, the x402/Solana payment rail, and an alternative HTTPS endpoint. It stops short of describing rate limits or error handling, but for a simple lookup the added transparency is substantial.

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 three sentences: the core definition, concrete examples, then the operational constraints and payment details. It is front-loaded with the most important information and contains no redundant or filler text. Every sentence contributes value.

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 read-only lookup with no output schema, the description covers input range, return semantics (place or 0), examples, and payment requirements. The only slight gap is a lack of detail on what a 'Higgs prime' is, but that is likely domain knowledge the agent does not need to invoke the tool correctly. Overall, it is complete enough for confident use.

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?

With 0% schema description coverage, the single parameter n is only constrained by min/max in the schema. The description compensates by explaining that n runs from 1 to 2000 and by providing illustrative examples (2 → 1, 19 → 7, 17 → 0). This adds interpretive meaning beyond the raw schema, though it does not explain what happens for out-of-range values.

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 specifies the exact operation: returning the 1-based index of n in the Higgs primes for exponent 2, with a clear fallback of 0. It gives concrete examples (2 is place 1, 19 is place 7, 17 is absent) that remove ambiguity. The verb+resource is unmistakable and distinguishes this tool from sibling lookups like higgs, higgs_count, or higgs_gap.

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?

The description implies the tool is used to find the position of a given integer in the Higgs prime sequence, and the examples clarify the domain. However, it never explicitly states when to use this tool versus siblings such as higgs, higgs_count, or higgs_next, nor does it mention exclusion conditions. The implied usage is adequate but not directive.

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