TxWhy

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

No annotations are provided, so the description carries the full burden. It usefully discloses a read-only, fast profile and the prerequisite that the transaction actually landed on mainnet, but says nothing about auth requirements, rate limits, or behavior for pending/never-landed signatures.

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?

Two tight sentences with zero filler; the capability and its outputs are front-loaded, and the routing hint to repair_transaction is placed last where it belongs.

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 does the work of describing what comes back (failing instruction, error name, cause, fix), which is the right call. The remaining gap is behavioral: an agent still lacks auth/rate-limit context that annotations would normally supply.

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?

Only one parameter and the schema already documents it fully (100% coverage), including the explorer-URL alternative form. The description adds no format or syntax detail beyond the schema, so the baseline 3 applies.

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 (diagnose a failed transaction) and enumerates the exact outputs: failing instruction in the call tree, named error, cause, and fix. It also names the sibling it is not (repair_transaction), so an agent can separate the diagnostic path from the repair path without reading schemas.

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 condition (a transaction that landed on mainnet and failed) and explicitly routes to repair_transaction when the goal is a working transaction. It does not, however, address how it differs from the other close sibling, explain_error, leaving some selection ambiguity.

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

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

With no annotations, the description carries the full burden. It usefully states the lookup's coverage (1,800+ named errors, major programs plus runtime errors), which tells the agent how authoritative the answer will be. However, it says nothing about read-only behavior, what happens for an unknown code, or whether programId matters for runtime errors.

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?

Two sentences, zero waste, and the core purpose is front-loaded before the usage cue. Every clause earns its place by either defining the capability or qualifying the input it accepts.

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 two-parameter lookup with 100% schema coverage and no annotations, the description covers purpose, input shape, and data coverage. With no output schema, a brief note on the returned form (or behavior on an unknown code) would close the remaining gap, but nothing essential to invoking it correctly is missing.

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 description coverage is 100%, so both parameters are already documented, including the 'number or hex string like 0x1771' format. The description's re-use of 6001/0x1771 as examples adds only marginal reinforcement and no new syntax or constraint detail. Baseline 3 applies when the schema does the heavy lifting.

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: 'Looks up what a custom program error code means for a given program.' It also discloses the data backing the lookup (1,800+ named errors plus runtime errors). It doesn't name the sibling tools, but the 'when you only have a code' framing implicitly separates it from diagnose_transaction, which operates on a whole transaction.

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?

'Use it when you only have a code such as 6001 or 0x1771 from a simulation or an RPC response' gives a concrete triggering condition with example inputs. No explicit when-not or named alternative (e.g. diagnose_transaction) is given, 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.

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

With no annotations, the description carries the full burden and does so richly: the returned transaction is UNSIGNED and must be signed and sent within ~60 seconds, it has been simulated against live mainnet state, exactly one input is accepted, and specific failure classes (insufficient funds, private program errors) are declared unfixable rather than silently re-broken. It also bounds the slippage change to at most 25% against the user.

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?

A dense but front-loaded paragraph that opens with what the tool does and closes with the actionable constraint (sign and send within ~60s). The rescue-mechanism inventory (blockhashes, compute units, fees, slippage per venue) is long but each item is decision-relevant, so little is wasted.

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 repair tool with no output schema and no annotations, the description covers inputs, return artifact (rebuilt unsigned transaction), post-call obligations, and non-repairable cases. An agent has everything needed to call it correctly and handle the result.

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, but the description adds the mutual-exclusivity constraint ('pass exactly one of transaction or signature') and the timing distinction (signature = already landed and failed; transaction = signed or unsigned, before or after a send) that the schema alone does not express.

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 ('repair ... a Solana transaction'), then sharpens it: finds the cause and returns a rebuilt, unsigned, mainnet-simulated transaction. This clearly separates it from diagnose_transaction and explain_error, which only tell you what went wrong rather than producing a fixed artifact.

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 concrete usage conditions ('a transaction that failed, or one you are about to send', before or after a send) and an explicit exclusion ('when the failure cannot be fixed ... it says so'). It never names the sibling tools diagnose_transaction or explain_error, so the agent gets no explicit routing guidance for the diagnose-vs-repair choice.

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