admin_caller_id

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

With no annotations provided, the description bears full responsibility for behavioral disclosure. It only states 'look up', implying a read operation, but fails to mention any potential side effects, required authentication (admin role likely needed), behavior for missing numbers, or data sources queried.

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 of six words, containing exactly the essential information without any fluff. It is appropriately front-loaded and every word serves a purpose for a simple 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?

For a simple tool with one parameter and no output schema, the description provides the core function. However, it omits details about the return value (what constitutes 'caller information'), error handling, and any constraints. While minimal, it is functional but not fully complete for an agent to anticipate results.

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 already describes the only parameter (phone_number) with the description 'Phone number to look up', while the tool description adds 'by phone number' which is redundant. Since schema coverage is 100%, the description adds minimal value beyond the schema, resulting in a baseline score of 3.

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 uses a specific verb-resource pair 'Look up caller information by phone number', clearly indicating the action and resource. It distinguishes itself from sibling tools like admin_get_user or contacts_get, which target different entities. However, 'caller information' is somewhat vague and could be more specific.

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 provides no guidance on when to use this tool versus alternatives such as admin_get_user, contacts_get, or customers_get. There is no mention of prerequisites, context, or exclusions, leaving the agent to infer usage from the name alone.

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