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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds important behavioral context beyond annotations by disclosing the per-call price and x402 payment endpoint, which is material for invocation.

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 question and a compact list of returned account attributes. The price and payment URL add useful detail without excessive verbosity, though the question-style opening is slightly informal.

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?

There is no output schema, but the description compensates by listing the main fields and parsed account types returned. Combined with the fully documented input schema and read-only annotations, it gives enough context for an agent to call the tool 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?

Schema description coverage is 100%, and both parameters are documented in the schema, including the base58 address format and the optional payment signature. The description does not add parameter-level syntax or semantics beyond mentioning the price/payment mechanism, so 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?

The description states a specific resource and enumerates what the tool returns: owner program, lamports, executable flag, data size, and parsed account type. It clearly identifies the operation as inspecting a Solana address rather than fetching balances or transactions, though it does not explicitly name sibling alternatives.

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 opening question implies the use case: inspect a Solana address to learn what kind of account it is. It does not explicitly say when to choose this over siblings like solana_sol_balance, solana_token_balances, or solana_transaction, leaving alternatives to inference.

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