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

Annotations only cover safety (readOnly/idempotent/non-destructive); the description adds substantial behavior beyond them: two result tiers with their latency (~20-24 min behind head on Base), per-fill and envelope `finality` fields, and the guarantee that `status: "not_found"` is never returned for a seen transaction, so polling never regresses.

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 core verb and purpose, then the tier explanation; no filler sentences. It is dense with domain jargon ('finality-fenced') that may cost a first read, but every sentence carries operational meaning.

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?

An output schema exists, so return shape needn't be explained, yet the description still covers the two tiers, finality fields, and the not-found edge case — exactly what an agent needs to interpret results and poll 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 both parameters are already documented in the schema (txHash format, chainId discovery). The description adds only indirect context — that the hash must be a mined transaction and that chain affects indexing lag — which is useful but not new parameter-level semantics.

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 ('look up a submitted trade by transaction hash') and immediately frames the access path ('the by-tx path for crash recovery'), which separates it from the fill-enumeration siblings such as list_trade_fills.

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 trigger — crash recovery / polling a known transaction — and an action rule ('Act on provisional; settle on finalized'). It does not name an explicit alternative (e.g., list_trade_fills when you don't have a hash), so it stops short of full routing guidance.

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