send_contact

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

No annotations are supplied, so the description carries the full disclosure burden for what is a message-sending mutation. It says nothing about what happens when chat_id is omitted, whether the contact posts into a chat versus a private target, permissions needed, or failure modes; only the output schema covers the response side.

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 short sentences, front-loaded with the action and its purpose, with no filler. The bilingual duplication is redundant for an English-reading agent but reads as intentional locale support rather than noise.

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?

The tool is simple and has an output schema, so return values need no coverage, but for a send/mutation tool with zero annotations and zero schema descriptions the definition is too thin. An agent still cannot tell how chat_id behaves or how the contact is transmitted, which are the two decisions it must make before calling.

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 description coverage is 0% across four parameters, so the description must compensate and largely does not. 'vCard contact' loosely implies first_name, last_name and phone_number, but chat_id and its default-null behavior are entirely unexplained in both schema and description.

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?

States a specific verb and resource ('Send a vCard contact') plus the user-facing effect (saving to the address book), which distinguishes it from send_text_message and the media siblings. It does not explicitly name an alternative, but 'vCard contact' is specific enough for an agent to route correctly.

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?

There is no when-to-use guidance versus siblings like send_text_message or send_local_document, and no statement about targeting (chat_id) or why a vCard would be preferred over sending a text with contact details. The only hint is the address-book framing, which is implied rather than directive.

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