Add to Contact List

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

No annotations, so description must cover behavior. Discloses auto-creation of minimal contacts but omits details like idempotency, duplicate handling, list existence checks.

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 concise sentences, each essential. Front-loads purpose, then adds behavioral detail. No wasted words.

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?

Covers main behavior and auto-creation. Lacks details on error states (e.g., list not found) and return values, but overall adequate for a simple tool.

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%, but description adds meaning: specifies that entries can be contact IDs or phone numbers, and clarifies auto-creation for phones.

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?

Clearly states verb (add), resource (contacts to list), and method (by ID or phone number). Distinguishes from sibling tools like create/remove list.

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?

Indicates two ways to add contacts (ID or phone) and notes auto-creation for phone numbers. Does not explicitly state when to use vs alternatives or provide exclusions.

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