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

Goes well beyond the annotations: discloses the block-range cap (1-1,000, default 50), the 100-log return ceiling, per-call pricing ($0.01 via x402/card key), a free tier of 25 calls, and that failed calls are free. The line "each call is charged, so repeats are not free" actively explains the idempotentHint=false annotation, and "changes nothing" reinforces readOnlyHint with concrete consequence.

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 what the tool returns and how to scope it, then usage routing, then cost. The pricing/key sentence is somewhat dense but justified because cost changes agent behavior; the closing "reads or computes only" clause partially duplicates readOnlyHint.

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 3-parameter read tool with no output schema, the description covers scope limits, return contents, the sibling alternative, and payment mechanics. An agent has everything needed to decide whether to call it and what to expect back.

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 baseline is 3; the description adds modest value by restating the block window and default, spelling out that topic0 is the 0x 32-byte event signature hash, and giving a worked address example. It does not add format details the schema lacks (e.g., address checksum expectations or topic0 hex length enforcement).

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 ("contract event logs on Ink (eth_getLogs)"), defines the scan window, and describes the return shape (up to 100 logs with block, transaction hash, topics). It also distinguishes itself from the nearest sibling by naming ink_receipt for single-transaction outcomes.

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 an explicit positive use case ("watch transfers or contract events") and names the alternative ink_receipt with the condition that selects it. It does not address overlap with ink_token_transfers, which is the more direct sibling for transfer-watching, leaving one routing decision to inference.

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