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

No annotations exist, so the description carries the full burden. It does disclose important behavior: the transaction is unsigned, the server never sees or holds private keys, and change returns to the sender. It says nothing about network/fee handling, error modes, or whether this touches chain state, which for a transaction-building tool is a notable gap.

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, purpose front-loaded ahead of the optionality caveat, with the non-custodial guarantee attached to the signing step it affects. No sentence is redundant.

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 2-parameter transaction builder with no annotations and no output schema, the description covers what the tool produces, who signs, and that it is skippable. It falls short only on api_key semantics and the format of the returned unsigned transaction.

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 0%, so the description must compensate. It explains from_address's role clearly through the fund flow, but gives no format guidance (address type/chain) and never mentions api_key at all, leaving half the parameters semantically undocumented.

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 (build), a specific artifact (unsigned transaction), and the exact fund flow: mint fee from from_address to the operator with change returned. An agent can distinguish this from mint and prepare_atomic_mint without opening any schema.

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?

Explicitly frames the tool as optional and tells the agent it may pay with any tool of its choice and skip this one. Missing is the sequencing context (e.g., when in the mint flow this is actually needed) and any named alternative sibling.

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