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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds genuinely non-schema behavioral context: read-only access pattern and, importantly, a pricing/charging model ($0.002 USDC per successful call, x402 on Base/Solana/Arc, failed calls free). This is valuable operational detail an agent needs before invoking.

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 return contents and compact, with no filler sentences. The parenthetical field lists are dense but on-topic. Slightly list-heavy rather than flowing, but efficiently sized.

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 the description need not explain return values, yet it does describe them — mildly redundant but reinforces what the agent gets. Combined with pricing and read-only disclosure, the definition is complete enough to call correctly. The only real gap is usage routing, which is scored separately.

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?

There is a single required parameter with 100% schema description coverage ('Account or mint address, base58'), so the schema already carries the semantics. The description notes that token accounts and mints are parsed, which loosely implies the address may be either, but adds nothing the schema doesn't. Baseline 3 applies.

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 the resource (a Solana account) and enumerates what it returns: lamports, SOL/USD value, owner program, executable flag, data size, plus parsed token/mint fields. This is a clear specific resource lookup. It does not, however, name or distinguish itself from near-siblings like solana_token, solana_wallet, or rpc_solana, so it stops 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 never says when to use this tool versus alternatives such as solana_token (which likely covers mint metadata) or rpc_solana (raw RPC). 'Read-only over Solana JSON-RPC' is a mild context hint but not usage guidance. No prerequisites, exclusions, or routing are given.

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