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

No annotations exist, so the description carries the full burden and does so: it discloses validation gates (network check, confirmed receipt, duplicate tx_hash replay protection, sender/recipient/amount matching), non-obvious traits like relayer top-level senders and bundler-multiple-UserOperation edge cases, and concrete side effects (records donation, increments campaign funded_amount, returns donation_id/status/tx_hash).

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?

Despite being a dense paragraph, it is front-loaded with flow position and required inputs, and every sentence supplies a distinct constraint (replay, relayer, bundler, mismatch handling, side effects). Some edge-case sentences could be split for scannability but none are filler.

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?

For a high-complexity mutation tool with no annotations and no output schema, the description covers validation preconditions, failure modes, side effects, and return fields — everything an agent needs to invoke it correctly and interpret the result. Only caller auth/permissions are unstated.

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 50% — amount and tx_hash have no schema descriptions — but the text compensates: tx_hash must be the actual chain transaction hash, is subject to one-record-per-hash replay protection, and amount must equal the matched Transfer event amount. campaign_id is only lightly reinforced ('correction' caveat) and relies on the schema for its format.

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 a specific action ('Step 2 of the MCP donation flow') and spells out exactly what the tool verifies and records: network, receipt, replay protection, canonical USDC Transfer event, then recording the donation and incrementing funded_amount. It implicitly separates itself from the sibling 'donate' by framing itself as step 2, though it never names that sibling outright.

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?

Strong exclusion guidance: it says a different transfer already in a recorded transaction 'cannot be recorded through this tool' and instructs the agent to reconcile and report rather than resend. What's missing is an explicit pointer to the sibling 'donate' as the step-1 prerequisite or to 'get_campaign_donations' for reconciliation.

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