find_document_threads

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

Annotations already declare readOnlyHint=true. The description does not add behavioral context such as side effects of syncBefore parameter (e.g., index refresh). With annotations present, the bar is lower, but the description provides no extra transparency beyond the schema.

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?

Two sentences, zero wasted words. The first sentence captures the core purpose; the second provides usage guidance and alternatives. Perfectly sized and 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?

With no output schema, the description should explain what the tool returns (e.g., thread IDs, metadata). It does not describe the return format. However, given the usage guidelines and parameter details, it is adequate for basic invocation. Could be more 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?

Schema coverage is 100%, so the schema already documents all parameters. The description lists example categories but adds no semantic detail beyond the schema definitions. Baseline 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 the action ('Find'), the resource ('email threads'), and the scope ('likely containing important document attachments...'). It distinguishes from siblings by noting it works without knowing exact sender or subject, and explicitly names an alternative tool for custom queries.

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 says when to use ('locate attachment-heavy threads by category without knowing exact sender or subject') and when not to ('Prefer search_indexed_emails with hasAttachment:true for custom attachment queries beyond the built-in categories').

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