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

With no annotations provided, the description carries the burden and does a solid job: it discloses the cost ($0.09 via x402), the live data source (Blockscout), and the read-only nature ('read agents'). It does not explicitly say 'does not modify state' or mention auth/error behavior, but the intent is clear and there is no contradiction.

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 dense but uses every clause for useful information. The first sentence is a long run-on but front-loads the core purpose. Subsequent sentences add use cases, chains, and value proposition. It is slightly overloaded but well-structured for an AI agent that needs rich context.

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?

Given there is no output schema, the description fully explains what the tool returns: plain-English explanation, list of asset changes, status, fee, and decoded method. It also covers supported chains and the use case rationale, making it complete for a complex tool with no structured output definition.

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 67%: hash and chain have good descriptions, but x_payment is undocumented. The description adds context by mentioning the cost and 'via x402,' which implies the payment parameter's purpose, but it doesn't explicitly tie this to x_payment. Overall, it adds some meaning beyond the schema but not completely.

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 opens with a specific verb and resource: 'decode any transaction by hash into a plain-English explanation,' then enumerates concrete outputs (swap, transfer, approval, asset changes, status, fee). It also differentiates from sibling tools by saying 'not just confirm it landed,' explicitly contrasting with chain_transaction_status.

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 states exactly when to use this tool: 'The read agents make to UNDERSTAND a tx, not just confirm it landed: for wallet UX, accounting, risk, dispute and trading agents.' It also names the alternative (chain_transaction_status) by implication and lists supported chains, providing clear context without ambiguity.

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