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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and closed-world, so the safety profile is covered. The description adds that this is a deterministic formula and constrains argument wrapping, but says nothing about defaults (e.g. 5000 lamports per signature) or behavior when optional fields are omitted.

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 formula is front-loaded and earns its place, but the trailing sentences ('Follow its required fields and exact choices', 'Supply units or modelVersion only when listed in inputSchema') are generic boilerplate that restates schema behavior rather than adding information.

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?

An output schema exists, so return values need not be explained, and the formula covers the core computation. However, with a nested inputs object of five fields at 0% schema description coverage and no annotation on defaults or unit expectations, the definition is only minimally complete.

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% stated schema description coverage, the description carries the load and does explain the role of each term in the formula: signatures, lamports per signature, compute-unit limit and micro-lamports per CU, plus the ceil and division-by-1,000,000 steps. It still leaves sol_price and the signatures/compute_unit_limit field meanings undocumented.

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 names the exact resource (Solana fee) and gives the verb-by-formula: signatures x lamports per signature plus compute-unit pricing. That clearly separates it from the BTC and EVM fee siblings, though it never names those alternatives explicitly.

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 only implied by the formula and the Solana scoping; there is no explicit when-to-use or when-not-to-use statement. The remaining guidance ('Put tool fields inside inputs', 'Do not pass the REST calculator field') is invocation mechanics rather than tool selection guidance.

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