get_thread

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

With no annotations, the description carries the burden of explaining behavior. It does this well by disclosing what each format returns and the relative cost ('metadata is headers+snippet only (cheap); plain adds the text body; full adds HTML and attachment metadata'). It does not mention auth or error behavior, but for a read-only thread fetch the format semantics are the main behavioral detail.

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, tightly written sentence. The core purpose is front-loaded, followed by compact, useful format details. There is no redundant or filler content.

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 description covers the key decision-relevant behavior—format and cost—and an output schema exists, so return structure need not be explained. It is slightly incomplete because it does not clarify the account/thread_id parameters or give any sibling routing guidance, but it is mostly sufficient for calling the 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?

Schema description coverage is 0%, so the prose must compensate. It thoroughly explains the format parameter's values and meaning, but account and thread_id are left entirely to inference from their names despite being required parameters. This is a clear gap.

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 clear action and resource: 'Get messages on a thread', which distinguishes it from single-message operations like get_message. However, it does not explicitly differentiate itself from sibling tools such as messages_list or get_message, so it stops short of 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 gives no guidance on when to prefer get_thread over alternatives like get_message or messages_list. It explains format tradeoffs, but not the conditions that should lead an agent to select this tool rather than a sibling.

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