ringcentral_list_external_contacts

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

No annotations are provided, so the description carries the full behavioral burden. It discloses the HTTP method (GET) and the default behavior for extension_id ('~' for the current extension), which implies a read-only operation. However, it does not explicitly state that it is non-destructive, mention authentication requirements, rate limits, or pagination behavior beyond having page and per_page parameters. The GET endpoint is useful context, but more explicit transparency would be beneficial.

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 structured as a concise docstring: a one-sentence summary, the API endpoint, and a bulleted list of arguments. Each line is informative and adds value. It is not overly verbose, though the API endpoint line could be considered extra but is useful for technical clarity. Overall, it is well-organized and front-loaded with the core purpose.

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 moderate complexity of a list operation with filters and pagination, the description covers the tool's purpose, API endpoint, and all parameters. The presence of an output schema means the return value does not need to be described in the tool description. It lacks explicit guidance on alternatives or broader context like authentication, but within the expected scope for a RingCentral tool in this set, it is reasonably complete.

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 has 0% description coverage, so the description must compensate. It adds semantics for all five parameters: extension_id with default '~', starts_with as a name filter, phone_number as a filter, page as page number, and per_page as results per page. This goes beyond the schema's bare property names. However, it does not elaborate on types, ranges, or formatting (e.g., whether page is 1-indexed), but it is sufficient for an agent to understand the intended usage.

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 begins with 'List an extension's personal address-book contacts,' which clearly states the verb (list), resource (personal address-book contacts), and scope (an extension). This distinguishes it from the sibling ringcentral_list_internal_contacts, which likely targets internal directory contacts. The API endpoint further specifies exactly what is called.

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 properly explains what the tool does but does not explicitly state when to use this tool versus alternatives. The name and 'personal address-book' wording imply it is for external contacts, while ringcentral_list_internal_contacts would be for internal ones, but no direct comparison or exclusion is given. Usage context is implied rather than explicit.

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