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

Adds real context beyond the annotations: the $0.001 USDC x402/Solana payment model, a per-call cost implication, and an HTTPS endpoint for the same operation. It also discloses domain limits (n in 0..4096, zero modulus rejected). It does not state what happens on rejection (error vs charge) or whether failed calls are billed.

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 operation, then constraints, then cost and endpoint. Four short sentences, each carrying distinct information, with no filler.

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?

No output schema, and the description partially compensates by stating the residue is smaller than the modulus. However, it never defines T(n) as the Tribonacci number, nor the output encoding (integer vs decimal string) for a modulus up to 600 digits, which is the main ambiguity for a math-compute tool.

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 params, and it partly does: mod is a positive decimal with zero rejected (a constraint the regex ^[0-9]{1,600}$ alone would not imply) and n's range is restated. It does not explain that mod is accepted as a string for arbitrary-precision values up to 600 digits.

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?

States a concrete operation, T(n) mod m, with the domain constraints. It is clear enough to distinguish from tribonacci/trib_index/trib_sum by the modular reduction, though it leans on the name 'trib' to convey that T is the Tribonacci sequence rather than defining it.

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 over siblings such as tribonacci, trib_index, or trib_mod alternatives; the only usage rule given is the modulus constraint (positive, zero rejected). An agent must infer selection from the name alone.

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