transactions.preparePrepares an unsigned transaction envelope for pinned Rootstock targets, returning it before policy approval so it can be reviewed or signed.
Return an unsigned policy-unapproved transaction envelope, only for pinned Rootstock targets.
| Name | Required | Description | Default |
|---|---|---|---|
| chain_id | Yes | ||
| transaction_json | Yes |
Changes observed during successful MCP inspections.
v0.9.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover safety (readOnlyHint=true, idempotent, non-destructive, closed-world); the description adds genuinely new context by declaring the result is unsigned and not yet policy-approved. It does not say what happens for non-pinned chains or what the caller should do next with the envelope.
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 single front-loaded sentence with no filler. It is arguably too terse for the amount of undefined jargon packed into it, but nothing 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?
No output schema and no parameter documentation mean the description should explain the envelope payload and the meaning of 'pinned'. It omits both, leaving the agent unable to construct transaction_json or know how to consume 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 0% with two required parameters, so the description carries the full burden — and it explains neither. 'pinned Rootstock targets' hints that chain_id must be a supported chain, but transaction_json's expected shape (the critical unknown) is never described.
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?
Specific verb+resource: returns an unsigned transaction envelope, and it distinguishes the scope ('only for pinned Rootstock targets') from sibling transactions.send/simulate. It stops short of full clarity because 'policy-unapproved' and 'pinned' are undefined jargon an agent must already know.
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?
'only for pinned Rootstock targets' is an implicit usage constraint, but no alternative is named (transactions.simulate, policy.evaluate, transactions.send) and no when-not-to-use is stated. The agent can infer this is a pre-signing step but must guess the ordering.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.