get_thread_brief

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 discloses that the tool returns a summarized view (non-destructive implied) and lists output contents. However, it does not explicitly state that it is read-only or mention any side effects. Adding an explicit 'does not modify any data' would elevate it to a 5.

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 two concise sentences with no fluff. The first sentence states the output, the second provides usage guidance. Perfectly front-loaded and efficient.

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 no output schema, the description adequately explains what the tool returns (previews, attachments, next action). It covers the single parameter and use case. It does not mention error conditions or limitations, but for a simple read tool it is mostly complete.

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 single parameter 'threadId' is well-described in the input schema (100% coverage). The description does not add new semantic details beyond restating the parameter name in context. Baseline of 3 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 returns a 'summarized view of a single thread' and lists specific components (previews, attachments, next action). It also explicitly distinguishes from the sibling tool 'get_thread_by_id' by contrasting 'summarized view' vs 'full raw thread data.'

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 provides explicit guidance: 'Use for a quick status check... without reading every message' and 'Prefer get_thread_by_id when you need the full raw thread data.' This clearly tells when to use this tool and when to use an alternative.

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