Get contact

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

With no annotations and no output schema, the description carries the full burden, but 'Fetch a contact' largely restates the tool's name and does not disclose behavior such as not-found handling, exact vs. partial match, authorization requirements, or return shape. It implies read-only, but adds little beyond the title.

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?

One sentence, front-loaded, and free of filler; every word contributes. It is appropriately sized for a simple single-parameter lookup tool.

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 definition is largely complete for a one-parameter read operation: the schema fully describes the phone format, and the description states the operation and key. The absence of return-shape or not-found behavior is a minor gap given no output schema, but the simple getter context makes the tool callable without further information.

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 schema covers the only parameter with rich E.164/national format guidance, so the description does not need to add parameter details. It reinforces that 'phone' is the lookup key, but does not add meaning beyond what the schema already provides.

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?

Description uses a specific verb ('Fetch'), a clear resource ('contact'), and the lookup criterion ('by phone number'), which distinguishes it from siblings such as gambot_get_contact_fields or other getters. The tool's intent is immediately actionable.

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 phrase 'by phone number' gives a clear trigger condition: use this tool when you need a contact record and have a phone number. It does not enumerate when-not-to-use alternatives, but no competing get-contact-by-other-key tool exists among the siblings, so exclusions are not strongly needed.

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