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

Annotations already cover readOnly/idempotent/openWorld, and the description adds real behavioral context on top: the cost model (25 free calls/day, then $0.01 USDC per call via x402), the 'mainnet-beta (real money)' default, and a failure-mode promise (names the failing program and the fix). This is substantive disclosure beyond structured fields.

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 primary use case and what it returns, with cost and docs citation at the end. Dense and mostly waste-free, though the output enumeration slightly restates the purpose sentence and the pricing sentence is long.

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?

With no output schema, the description carries the return-value burden and does so: it lists result, fee, balance deltas, programs, and failure cause, plus cost, default network, and a docs pointer. An agent has everything needed 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?

Schema coverage is 100%, so the schema already documents both params fully (including 'never make one up' and devnet guidance). The description restates tx_id and network with a slight nuance ('real money'), which adds marginal value over the schema. 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 and resource ('reads a confirmed transaction and returns...') and enumerates the actual outputs: success status, fee, per-wallet SOL/token balance changes, programs used, and failure reason. It is clear and detailed, but it never names the overlapping siblings (why_failed, check_tx) it must be distinguished from.

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?

Gives a clear triggering context: 'Run after a transaction lands (or fails) to report what really happened, instead of guessing from logs.' That contrasts it with ad-hoc log reading, but provides no explicit when-not-to-use or sibling routing (e.g., why_failed for a failure-only lookup).

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