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

Annotations already declare readOnly, idempotent and non-destructive, so the safety burden is lifted. The description adds genuinely non-obvious context: per-call pricing ($0.001 USDC via x402 on Solana) and a direct HTTPS endpoint alternative — details that materially affect invocation decisions.

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?

Three compact sentences, front-loaded with the core semantics and capped with pricing and the HTTPS fallback. Nothing is padded; the range and example are the only slight redundancy with the schema.

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 single-parameter, single-value lookup with no output schema, the description covers indexing convention, bounds, sequence definition and cost model. The only minor gap is that the return type (a single integer term) is implied rather than stated outright.

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 the load, and it does: it specifies 1-based indexing (not derivable from the schema) and restates the valid range 1–100000. It also gives worked examples (sequence start, term 7 = 1) that confirm the indexing convention.

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 precise resource and semantics: 'the nth Kolakoski term, using a 1-based index,' and defines the sequence explicitly. It lets an agent distinguish this from prefix/sum/run variants implicitly through 'nth term', though it never names the sibling tools.

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?

Usage is implied rather than stated: an agent must infer that this is for a single indexed term versus kolakoski_prefix, kolakoski_run, kolakoski_check or kolakoski_sum for bulk/validation work. No explicit when-to-use or when-not guidance is given.

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