get_thread

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

No annotations are provided, so the description carries the full burden. It does disclose what comes back (headers, plain-text body, attachment names — notably not attachment content or HTML), which is real value, but it says nothing about read-only guarantees, permissions needed, or what happens when the thread or account is invalid.

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 the core action and returned fields front-loaded, followed by the one parameter clarification that needs it. Nothing is padded or redundant.

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 two-parameter read tool with no output schema, the description covers purpose and return shape adequately. However, with zero annotation and zero schema-description coverage it should also state the default-account behavior and any lookup-failure semantics, which it does not.

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 both parameters. It clarifies that `account` is an email or alias, which the bare any-of string schema does not convey, but it leaves `thread_id` format undefined and does not say what happens when `account` is omitted (schema default is null).

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 uses a specific verb and resource ('Read all messages in a thread') and even enumerates the payload (headers, plain-text body, attachment names), so an agent can tell this fetches a whole thread by id rather than searching. It does not explicitly contrast itself with the sibling search_emails, which keeps it 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?

Usage is implied: you call this when you already have a thread_id and want every message rather than a search result set. There is no explicit when-not guidance, no mention of when to prefer search_emails, and no note on prerequisites or failure behavior.

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