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

With no annotations, the description carries the full load and does disclose two non-obvious traits: result ordering (newest first) and row-level access scoping (owner/office see all, field workers see only threads for assigned jobs). It stops short of covering pagination behavior or whether the limit is a cursor or a hard cap.

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?

Two tight sentences with no filler, and the identifying information (what it returns, in what order) is front-loaded before the access-scoping caveat.

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?

An output schema exists, so return values needn't be explained, and the access model is covered. But a required shop_id parameter is entirely undocumented and pagination semantics for limit are absent, leaving real gaps for a listing tool with zero annotation coverage.

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%, so the description must compensate for two undocumented parameters, and it does not: neither the required shop_id (uuid) nor the limit (1-200) is mentioned or explained. An agent gets no guidance on what shop_id scopes or how limit interacts with the 'newest first' ordering.

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?

States a specific verb+resource ('Text threads with customers') plus an ordering guarantee ('newest first'), which is more than the bare name provides. It does not explicitly distinguish itself from the singular sibling phone_thread or from phone_calls, so an agent must infer the list-vs-single split from the name alone.

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 visibility sentence implies this is the browse/list view of SMS conversations, but there is no explicit 'use this when' or exclusion pointing to phone_thread for a single conversation or phone_calls for call history. Usage is implied by the plural name rather than stated.

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