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

Annotations contain only a title, so the description carries the behavioral disclosure burden. It clearly signals a read/list operation and caller scoping, but it does not mention pagination behavior, ordering, authentication details, or any side effects. This is adequate but not rich.

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?

A single sentence with no filler, front-loaded with the action and resource. Every word contributes to understanding the tool's 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?

For a simple list tool with two optional pagination parameters and no output schema, the description states the core purpose and ownership scope. However, it omits pagination semantics and return format details, making it minimally viable rather than fully 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?

Schema description coverage is 0%, and the description does not mention limit or offset at all. The parameter names are conventional, but the description adds no meaning about how pagination works, leaving the agent without any schema or textual guidance.

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'), a concrete resource ('stored message ids'), and a clear scope ('owned by the caller'), which makes the tool's purpose immediately understandable and distinguishable from siblings like sms_send or sms_source.

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 ownership qualifier implies when this tool is relevant, but the description gives no explicit guidance about choosing sms_sources over alternatives such as sms_history, sms_source, or chat_sources. No exclusions or comparison to siblings are provided.

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