anvil_generate_etch_sign_urlGenerate a one-time embedded signing URL for a specific signer in an Etch packet (for iframe/redirect signing flows). GraphQL mutation: generateEtchSignURL. Returns { url }.
| Name | Required | Description | Default |
|---|---|---|---|
| signer_eid | Yes | The signer eid (from the packet's documentGroup.signers). | |
| client_user_id | Yes | Your app's stable id for the signing user (ties the session to your user). |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already mark destructiveHint=true; the description adds that it's a one-time URL and returns {url}, but does not elaborate on the destructive nature (e.g., URL expiry or side effects).
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, front-loaded with the main purpose, no wasted words. Every sentence adds value: purpose, GraphQL mutation, return type.
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?
Description covers purpose, parameters, and return; given simplicity and annotation presence, it is mostly complete. Could mention that the URL is one-time use or has an expiration.
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% with clear descriptions; the tool description adds no additional semantics beyond the schema, which is adequate but not improved.
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?
The description clearly states it generates a one-time embedded signing URL for a specific signer in an Etch packet, distinguishing it from sibling tools like anvil_create_etch_packet and anvil_get_etch_packet.
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?
The description specifies the signing flow context (iframe/redirect) and implies use after creating a packet, but does not explicitly state when not to use or mention alternatives.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.