get_thread

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

Beyond annotations (readOnlyHint, idempotentHint), the description adds behavioral details: sorting by date_received ascending, threading dispatch method (Tiered IMAP, AppleScript fallback), and a known limitation about subject rewrite. No contradiction with 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?

Description is front-loaded with main purpose and then provides technical details. Could be slightly more concise, but every sentence adds value. Good structure.

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 output schema exists for return values, the description adequately covers the tool's behavior, threading algorithm, limitations, and integration with sibling tools. Sufficient for accurate invocation.

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 100% for message_id. Description adds context that it is an 'Internal id of any message in the thread' and how it is used as anchor, which adds some value beyond schema.

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?

Description clearly states 'Return all messages in the thread containing the given message.' It details the lookup and reconstruction process, and the tool name 'get_thread' aligns with this purpose. Distinguishes from siblings like get_messages and search_messages.

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 explains how returned ids can be piped into search_messages or get_messages for further processing, providing a usage pattern. However, it doesn't explicitly state when to use this tool vs alternatives or when not to use it.

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