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

The readOnlyHint annotation already establishes that this is a safe read operation. The description adds page size and returned fields, but does not disclose ordering, pagination metadata, or other operational details beyond what the schema and annotations already imply.

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?

It is a single efficient sentence, front-loading the resource and scope and embedding the returned fields compactly. There is no wasted text.

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 read-only list tool with full schema coverage, the description is sufficient: it identifies the resource, returned fields, and pagination size. The schema handles the detailed pagination parameters.

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 100%, so the schema already documents both limit and start clearly, including defaults and next-page usage. The description mentions 100 per page but adds no parameter semantics beyond the schema.

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 gives a clear verb and resource: listing incoming text messages sent to the account's numbers. It also names returned fields, but it does not explicitly distinguish itself from nearby siblings like get_incoming_text or list_texts.

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 phrase 'people sent to the account's numbers' implies this is for browsing incoming messages rather than retrieving a single message or listing outbound texts. However, there is no explicit when-to-use guidance or named alternative for single-message retrieval.

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