Send Contact Card

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

Annotations already declare readOnlyHint=false and destructiveHint=false, so the safety profile is known. However, the description adds no additional behavioral context—it does not mention typing simulation (the delay param), formatting constraints, or any side effects. The description merely restates the tool's purpose and provides no new behavioral transparency beyond the annotations.

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 a single sentence with no wasted words. It front-loads the core action ('Send') and the resource ('WhatsApp contact card'), making it highly efficient.

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?

For a simple send operation, the description is complete enough. The schema covers parameter details, and annotations cover safety. The description lacks no critical information for basic use, though it could mention the delay parameter's role in typing simulation, but that is already documented in the schema. Minor gaps prevent a perfect score.

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?

The input schema provides 100% description coverage for all four parameters, including the meaning of delay, number, contact_name, and contact_phone. The description adds no additional parameter details beyond what the schema already specifies, so the baseline of 3 applies.

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 'Send a WhatsApp contact card (vCard) to a phone number' uses a specific verb ('send') and identifies a clear resource ('contact card (vCard)') and recipient ('phone number'). It clearly distinguishes this tool from siblings like send_text, send_audio, and send_location.

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 implies usage for sharing a contact card but does not explicitly state when to use it over alternatives or provide exclusions. The sibling tool list includes many send_* tools, but the description does not compare against them directly, leaving usage guidance implied rather than explicit.

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