Retrieve SIP messages for a specific phone number by ID, with cursor pagination and configurable page size.
Get Sip Messages For A Phone Number
| Name | Required | Description | Default |
|---|---|---|---|
| cursor | No | Used for fetching next page. Cursor is returned in the response. | |
| page_size | No | ||
| phone_number_id | Yes | The phone number ID. This is returned when a phone number is imported. |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=true. The description adds no behavioral context beyond the annotations, such as pagination behavior, rate limits, or authentication needs.
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 front-loaded sentence with no wasted words. It is appropriately sized for a simple list/get endpoint, though it could be more structured by mentioning pagination or filtering.
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 tool is low complexity and annotations carry the safety profile, but the description does not explain pagination or the missing page_size semantics, and there is no output schema to document return values. It is minimum viable but leaves gaps an agent might need.
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?
Schema description coverage is 67%, with page_size undocumented in the schema. The description implies the required phone_number_id but adds no clarifying meaning for it, cursor, or page_size 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?
The description states a specific verb and resource ('Get Sip Messages') and scopes it to a phone number, which differentiates it from the conversation-level sibling get_conversation_sip_messages. It stops short of explicitly naming or excluding that sibling.
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?
There is no guidance on when to use this tool versus alternatives such as get_conversation_sip_messages or list_phone_numbers_route. The only usage context is implicit in the phrase 'For A Phone Number.'
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.