swap_txn

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

With no annotations, the description carries the full burden and does disclose the key traits: the transaction is unsigned, no signing occurs here, the output is a base64-encoded transaction group, and signing is delegated to UluWalletMCP. It omits failure modes (no route found, insufficient liquidity) and whether slippage tolerance is enforced by this call.

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?

Three short sentences with zero padding, front-loaded with the action and followed by the output contract and the pool-discovery behavior.

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 six-parameter mutation-adjacent tool with no annotations and no output schema, the description covers the return shape (base64 transaction group) and the downstream signing step, which is the critical integration detail. It stops short of stating error behavior or that a quote should be obtained first.

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 all six parameters including slippage default and poolAppId are already documented in the schema. The description's pool auto-discovery note largely restates the schema's own poolAppId description, adding no new syntax or constraint detail, 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 ('Build unsigned transactions to swap tokens') plus the protocol (PactFi), which cleanly separates it from add_liquidity_txn, remove_liquidity_txn, and the read-only get_quote/get_pool tools.

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?

Usage is implied rather than stated: the description says the output is for signing via UluWalletMCP and that poolAppId is optional, but it never says when to call this versus get_quote first or what prerequisites (funded wallet, valid pool) must hold.

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