add_contact

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

Discloses critical behaviors: modifies .contacts.json, idempotent, updates on re-call, enriches with lastJobAt/lastCapability. No annotations present, so description carries full burden and does so thoroughly.

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 main action, no redundant text. Efficient and clear.

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 purpose, idempotency, enrichment, and update behavior adequately for a simple creation tool. Lacks error handling or return value details, but no output schema expected.

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 has no descriptions, but description adds meaning: npub identifies the provider, name and note are updatable fields. Baseline for 0% coverage is 4, and description compensates adequately though without detailed format constraints.

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 the tool adds a provider to the active agent's contacts file, with specific verb and resource. Distinguishes from sibling tools like list_contacts and remove_contact by focusing on addition and idempotent update.

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?

No explicit guidance on when to use vs alternatives, but the purpose is clear. Idempotency hint helps, but no direct comparison with siblings.

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