get_thread

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

Goes well beyond the readOnly/openWorld annotations: ordering ('oldest first'), deduplication ('each message once'), a hard cap ('at most 50, the newest'), metadata-only return, prompt-injection handling of message text, and the tag-scoped marker convention that bounds returned content. These are exactly the behavioral traits an agent needs and cannot get from the annotations.

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?

Front-loads purpose, ordering, and limits before the security boilerplate, and every sentence carries information. The marker-tag paragraph is long, but it is load-bearing for interpreting output rather than filler.

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?

With no output schema, the description covers return shape well: metadata only, ordering, cap, single occurrence per message, and the marker-line framing of content. An agent has enough to call it and interpret the result correctly.

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 coverage is 0% and both parameters are required with no documented meaning. The description indirectly explains where threading is searched ('its own folder, INBOX and Sent'), which loosely informs the folder argument, but 'uid' is never explained and no syntax or format is given, so most of the compensation burden is unmet.

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 and resource ('List the conversation one message belongs to') and immediately scopes it to earlier messages plus replies found via threading headers. It is clearly distinguishable from get_email ('Read a message with get_email') and search_emails.

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?

Explicitly routes the agent to get_email when the goal is to read message content, which is the main alternative an agent would otherwise confuse this with. It stops short of saying when get_thread itself is preferred over search_emails, so it is clear context rather than full when/when-not guidance.

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