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

Annotations already declare readOnly/idempotent/non-destructive/openWorld, so the safety profile is covered. The description adds genuinely extra context: pricing ($0.003, 10 free/day, x402 payment-required result), the error contract (isError for invalid input or upstream failure, not charged), dual token-program reads, and empty accounts counted as reclaimable rent.

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 value proposition, then usage, pricing and errors in a compact sequence. Dense but every clause carries useful information; only slightly long for a one-parameter tool.

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 format need not be explained. Given that, the description covers domain scope, alternative routing, cost model, and error semantics — everything an agent needs to call it correctly.

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?

Only one parameter with 100% schema coverage (pattern and Base58 format fully documented in the schema). The description adds no parameter-level detail beyond the schema, so the baseline 3 is appropriate.

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 specific verb+resource+scope: 'Everything a Solana wallet holds — SOL, SPL and Token-2022 tokens — valued in USD and sorted by value.' It names the sibling alternative (evm_address) and its domain constraint, so an agent can distinguish it from the many other wallet/address tools in the sibling list.

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?

Explicit 'When to use' section: Solana wallets here, EVM wallets via evm_address. Nothing is left to inference, and it even explains that evm_address is callable by name.

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