contact_list

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

With no annotations present, the description carries the safety burden and explicitly declares 'Read-only'. It also scopes the behavior to the current account. For a zero-parameter listing operation, this discloses the key behavioral trait; only minor details like output format or ordering are absent.

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 short, front-loaded sentence states the action, resource, scope, and read-only nature with no filler or repetition. Every word earns its place.

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 parameterless list tool, the description is largely complete: it names what is returned (contact handles) and the scope (account). It could improve by explicitly steering users to sibling tools for details, but that gap is minor given the simple invocation surface.

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 tool has zero parameters and the schema description coverage is 100%, so there is no parameter information missing. The description adds no parameter specifics, but none are needed; this is the appropriate baseline for a parameterless tool.

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 ('List') and resource ('contact handles'), enumerates the handle types (owner/admin/tech/billing), and scopes the operation to the account. This clearly distinguishes it from sibling tools like contact_info (detail lookup) and contact_create (creation).

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 is clear from 'List... in the account' when to use this tool: to enumerate contact handles. However, it does not explicitly name alternatives such as contact_info for details, or state when not to use this tool, leaving routing mostly implied.

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