update_phone_number_messaging_settings

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

No annotations are provided, so the description carries the full burden. It indicates this is a mutation tool ('update'), which implies it modifies data, but doesn't disclose behavioral traits like required permissions, rate limits, or side effects. The description adds some context about parameter handling (null, empty string, UUID), but lacks comprehensive behavioral details.

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 appropriately sized and front-loaded, with the purpose stated first. The Args and Returns sections are structured clearly. However, the 'Returns' section is vague ('Response data') and could be more specific, slightly reducing efficiency.

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 complexity (mutation tool with 2 parameters, nested objects, no annotations, no output schema), the description is moderately complete. It covers parameter semantics well but lacks behavioral context (e.g., permissions, side effects) and output details. It's adequate but has clear gaps for a mutation tool.

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 description adds significant meaning beyond the input schema. The schema has 0% description coverage and only shows 'id' and 'request' as parameters, while the description explains 'id' as 'The phone number ID to update' and introduces 'messaging_profile_id' and 'messaging_product' with detailed semantics (null to keep current, empty string to unassign, UUID to assign). This fully compensates for the schema's lack of coverage.

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 the tool's purpose: 'Update the messaging profile and/or messaging product of a phone number.' It specifies the verb ('update') and resource ('phone number'), but doesn't explicitly differentiate from sibling tools like 'update_phone_number' or 'update_messaging_profile', which is why it's not a 5.

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. It doesn't mention sibling tools like 'update_phone_number' or 'update_messaging_profile', nor does it specify prerequisites or exclusions. Usage is implied but not explicitly stated.

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