Read a message thread

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

The description reinforces the readOnlyHint annotation by explicitly stating it reads a thread and explains that an empty replies list means no answer yet. It goes beyond the annotation by describing the expected state of the output based on operator behavior, though it does not detail side effects (which is fine for a read operation).

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 concise, well-structured, and front-loaded with the primary purpose. It uses only a few sentences to convey the output, parameter source, and polling guidance, with no redundant or vague phrases.

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 tool's simplicity and the presence of sibling tools, the description is complete enough: it explains the output, the meaning of an empty reply list, and the expected polling behavior. It lacks an explicit output schema, but the described output contents are sufficient for an agent to use the result. Minor edge cases (e.g., errors) are not covered but are not critical for this read-only 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 schema already fully describes both parameters with examples, and the description adds the context that these come from the submission response, clarifying their origin. This extra context helps the agent know where to obtain the values, going slightly beyond the schema alone.

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 reads a message thread, listing the exact output contents (original text, replies oldest-first, answer status). It distinguishes itself from sibling tools like reply_in_message_thread or submit_human_task by focusing on reading rather than sending or submitting.

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 guidance on when to use the tool: after receiving a submission response, and it advises polling occasionally instead of in a loop due to human-speed responses. It does not explicitly mention alternatives or when not to use it, but the read-only nature is clear.

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