Get contact

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

With no annotations, the description fully bears responsibility for transparency. It discloses the tool's read-only nature, the required mutual exclusivity of identifiers, and the optional expansion, providing sufficient behavioral context without contradictions.

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 concise with two sentences, front-loading the purpose and key usage rule. Every sentence adds value with no unnecessary filler.

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?

Given the lack of output schema and annotations, the description covers the tool's purpose, parameters, and constraints well. It could be slightly improved by noting the expected return format (e.g., contact object), but overall it's adequate for the tool's simplicity.

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?

Although the input schema already describes each parameter (100% coverage), the description adds value by clarifying the mutual exclusivity constraint and the purpose of userDefinedIdentifier as an alternative to contactKey, enhancing understanding beyond the schema.

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 'Get a single person contact' with specific identifiers (ContactKey or UserDefinedIdentifier) and optional expansion, which distinguishes it from sibling tools like list_contacts (list) and update_contact (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?

It explicitly instructs to provide exactly one of contactKey or userDefinedIdentifier, guiding correct invocation. However, it doesn't explicitly state when not to use it or mention alternatives like list_contacts for non-single lookups, though it's implied.

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