mail_get_thread

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

With no annotations provided, the description carries the full burden and does a good job in parts: 'Reconstruct' signals a non-mutating, read-style operation, and the statement 'Embedded forwarded chains are not separate messages' surfaces a genuinely surprising behavior. It stops short of details like errors or response envelope, but the core behavioral trait is disclosed.

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 dense sentences, with the central operation and scope front-loaded and the important exception stated after. Every clause contributes new operational information rather than restating the tool name or schema.

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 together with the very detailed input schema provides enough to select and configure the tool: the required seed, optional folder and message bounds, and body modes are all recoverable from the schema, while the prose covers the returned content concept ('headers', 'body mode'). Without an output schema or annotations, one could still appreciate the thread-level return and non-mutating nature, though response shape details are left open.

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 documents 80% of the parameters with meaningful descriptions, so the description need not repeat them. The prose only echoes the concepts behind bodyMode and bounded reconstruction without adding new semantic details about seed, mailboxScope, or maxMessages beyond what the schema gives.

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 names a specific resource ('mailbox-local conversation') and a clear operation ('Reconstruct'), and it goes beyond a tautology by specifying 'complete per-message headers' and the 'requested body mode'. The clause about embedded forwarded chains not being separate messages distinguishes this threaded behavior from a simple message fetch.

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 wording implies this is the tool to use when a conversation-level reconstruction is needed, and the sibling mail_get_message reinforces that contrast. However, there is no explicit statement of when to prefer this over mail_get_message or when not to use it, so the guidance remains mostly implied rather than explicit.

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