send_contact_card

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

Annotations indicate a write operation (readOnlyHint=false) but description adds behavioral details: persistence to local cache, revocability via delete_message, and clear return format. No contradictions. However, it does not disclose any side effects or failures.

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 efficiently cover purpose, behavior, parameter interaction, and return value. No fluff; every clause adds value.

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 return value, main behavior, and reversibility. Lacks error handling details or rate limits but is adequate for a contact card tool with no output schema. Moderate complexity warrants this 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?

Schema coverage is 100% (all parameters described), description adds key behavior: synthesis of vCard when omitted, recipient format guidance. This enriches understanding beyond schema definitions.

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 clearly states the tool sends a WhatsApp contact card, describes the user-facing behavior (tappable, savable), and mentions persistence and reversibility. It distinguishes itself from siblings like send_message or send_file by specifying a contact card format.

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?

Provides implicit guidance by explaining when to omit vcard (synthesis from name+phone) but no explicit comparison to alternative tools for sending contacts (e.g., send_message with vCard text, send_file). Does not state when not to use this tool versus siblings.

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