get_thread

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

Annotations already indicate read-only and idempotent. The description adds details: chronological sorting, folder spanning, UID collision avoidance, and rewriting of folder/UID for user folders. No contradictions.

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?

Well-structured with sections (preferred, legacy, scope) and front-loaded main purpose. However, some explanatory text could be trimmed; still clear and organized.

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 complexity of IMAP threading, the description covers algorithm, limitations (forwards), and pitfalls (UID collisions). Even without output schema, it provides enough return value context.

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% (all parameters described). The description adds value by explaining the rationale behind messageId vs uid+folder and the default folder walk, but baseline is 3 due to full schema coverage, so 4 is appropriate.

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 it retrieves all messages in a conversation thread by walking In-Reply-To and References headers, specifying the verb, resource, and mechanism. It distinguishes from siblings like 'list_messages' by focusing on threading.

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?

It explicitly recommends using messageId over uid+folder due to UID collisions, explains the legacy alternative, and clarifies the scope (only reply chain, not forwards). Provides clear when-to-use guidance.

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