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

Annotations already cover read-only, idempotent, open-world, and non-destructive behavior, and the description adds important context: pricing ($0.001 USDC per successful x402 call on Solana), an HTTPS endpoint, and the valid input range. It does not describe return formatting or error behavior, but that gap is minor given the existing annotations.

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 examples, then supplies range, pricing, and endpoint details efficiently. Every sentence contributes useful information, though the structure could be slightly tighter.

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 one-parameter tool with no output schema and safety annotations already present, the description provides enough to call the tool correctly: operation, examples, range, cost, and endpoint. A brief formal definition of 'fibbinary' or explicit sibling routing would improve completeness.

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 states the input range and gives examples mapping n to output, but largely repeats the schema's min/max and does not formally define what a fibbinary number is or add much beyond illustrative examples.

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 precisely defines the operation: returning the smallest fibbinary number at least n, with concrete examples that remove ambiguity. It does not explicitly differentiate from sibling tools such as fibbinary, fibbinary_nth, or fibbinary_index, so it falls short of 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?

The description gives no explicit guidance on when to use this tool versus alternatives like fibbinary or fibbinary_nth. The operation name implies usage, but there are no stated conditions, exclusions, or sibling comparisons.

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