add_contact

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

The description goes far beyond the annotations, revealing signing behavior with Ledger, in-memory store fallback, unsigned flags, metadata sidecar for notes/tags, duplicate label replacement, duplicate address rejection, and resolution in send flows. This level of detail gives the agent complete understanding of all behavioral nuances.

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?

The description is well-structured with clear sections for different modes, but it is lengthy. While each sentence adds value given the complexity, a more concise front-loading of core behavior would improve it. Still, it earns a 4 for being informative without excessive redundancy.

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?

Given the tool's complexity (6 params, multiple modes, no output schema), the description is exceptionally complete. It covers all edge cases, return values (unsigned flags, anchorAddress), and interactions with other prepare flows. No gaps in context.

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 detailed parameter descriptions. The tool description adds minimal extra meaning for parameters beyond summarizing chain support; it does not enhance semantic understanding beyond the schema. Baseline 3 is appropriate.

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 explicitly states the tool's purpose: 'Save a label → address binding to the address book.' It distinguishes from siblings like list_contacts, remove_contact, and verify_contacts by focusing on the creation action with detailed mode-specific behaviors. The verb 'save' and resource 'address book binding' are specific and clear.

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 provides rich context for when to use the tool, detailing production modes with/without Ledger, demo mode, chain support, and duplicate handling. However, it does not explicitly compare with sibling tools or state when not to use it, missing the 'alternatives' criterion for a 5.

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