search_threads

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

With no annotations, the description carries full burden. It discloses the search scope, default vs hybrid behavior, and mentions that hybrid loads the embedding model. It doesn't cover rate limits or authentication, but for a read-only search tool, it provides sufficient behavioral context.

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 a single concise paragraph of four sentences, front-loaded with the main purpose. Every sentence adds value—scope, default/option, output, and usage intent. No fluff or repetition.

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 5 parameters, no output schema, and 15 siblings, the description covers the tool's purpose, filtering options (sources, hybrid), and intended use. It could mention the return structure more explicitly, but the essentials are present.

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%, so baseline is 3. The description adds value by explaining hybrid's purpose (on-device semantic similarity, higher recall) and that it loads the embedding model, which aids parameter understanding beyond schema descriptions.

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 tool searches AI coding-agent conversation threads across many specific tools, with keyword full-text by default and optional semantic search. It distinguishes from siblings like recent_threads and get_thread by focusing on search and recall of past decisions.

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 clear usage context: 'Use this to recall past decisions, prior solutions, or earlier discussion before redoing work.' It doesn't explicitly exclude alternatives, but the context and sibling names imply when other tools are appropriate.

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