add_signatory_to_document

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

Annotations already signal a non-read-only, non-idempotent mutation. The description adds valuable lifecycle context beyond annotations: the strict ordering dependency and the irreversible activation boundary. This helps an agent understand the operational impact of calling this tool at the wrong time.

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 dense sentences with no filler. The action is stated first, followed by usage frequency, prerequisites, and the critical activation constraint. Every sentence contributes essential information.

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?

The description covers the core workflow well: what the tool does, how to use it, its prerequisites, and the key lifecycle restriction. Optional parameters are not elaborated, but the presence of an output schema and the focus on the required flow keep this reasonably complete for an agent.

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 only 22%, so the description carries meaningful burden. It clarifies that name and email identify the signatory and that signatureRequestId/documentId come from prior API calls. However, optional parameters like phone, sequence, coordinates, and uniqueValidator are left unexplained, leaving gaps for non-basic usage.

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 uses a specific verb and resource: 'Adds a signatory (by name + email) to a document within a signature request.' It clearly distinguishes this from sibling tools like add_validator_to_signatory and add_observer_to_document by emphasizing the signatory role and the document context.

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?

It gives explicit when-to-use guidance: 'Use once per person who needs to sign that specific document.' It also states prerequisites (create_signature_request and add_document_to_signature_request) and a clear when-not: signatories cannot be added after activation.

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