search_threads

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

With no annotations, the description carries the full burden. It discloses that the tool returns compact summaries, is a fallback, and that full content requires `get_thread`. It does not mention potential rate limits or network behavior, but the key behavioral traits are clearly conveyed.

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 front-loaded with the most critical guidance (fallback status and preferred alternative), followed by a structured Args list. Every sentence is informative and there is no redundant or filler text.

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?

For a search tool with moderate complexity, the description covers all necessary aspects: purpose, fallback role, parameter semantics, and follow-up actions. The existence of an output schema means return values need not be detailed, and the description mentions the summary format sufficiently.

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 has 0% description coverage, but the description's Args section compensates fully. Every parameter is explained with meaning, examples (e.g., 'peer review', 'exam'), defaults, and usage tips (e.g., type filter values). This goes well beyond the bare 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 identifies this as a keyword search tool for threads, using the verb 'search' plus specific resource ('threads'). It also differentiates from the sibling tool `search_index` by labeling itself as a 'FALLBACK' option, making its distinct role unambiguous.

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?

Explicit guidance is provided: 'PREFER `search_index`' and 'Only use `search_threads` when the local index is unavailable or sync fails.' This directly tells the agent when to use this tool versus the alternative, and it also suggests following up with `get_thread` for full content.

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