get_thread_by_id

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

No annotations are provided, so the description must cover behavior. It states the tool fetches from the local index and returns full metadata, which implies read-only and completeness. However, it does not disclose potential performance implications, size of returned data, or any prerequisites beyond the thread ID. The description is adequate but lacks depth on behavioral traits.

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?

The description is three sentences, each serving a clear purpose: first explains what the tool does, second provides usage guidance, third suggests an alternative. No extraneous information, well front-loaded.

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 tool has one simple parameter and no output schema, the description covers all necessary aspects: purpose, what it returns, when to use it, and how the parameter relates to other tools. It is fully sufficient for an agent to select and invoke the tool 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?

The only parameter 'threadId' has a schema description 'Thread id from get_threads.' The tool description adds context by implying that the ID is obtained from a prior call to get_threads, which supplements the schema definition. This adds meaning beyond the 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?

The description clearly states the verb 'Fetch' and the resource 'complete normalized thread record', listing the included data (messages, participants, labels, metadata). It distinguishes itself from the sibling get_thread_brief by noting that this tool returns all messages while the sibling provides a summarized view.

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 explicitly states when to use this tool ('when you need all messages in a thread') and offers an alternative ('prefer get_thread_brief for a summarized quick view'). This provides clear guidance on tool selection.

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