get_threads

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

Annotations indicate readOnlyHint=true, and the description adds useful behavioral context: grouping by subject/participants, reliance on 'the local mailbox index', and the limitation that only subject and participants are searched. There is no contradiction with annotations, and the added detail goes beyond the basic safety hint.

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, front-loaded with the primary purpose, and each sentence provides distinct, non-redundant information: the core function, the general usage context, and alternative tool recommendations. It is concise and well structured.

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's moderate complexity, read-only annotation, and the presence of siblings, the description covers purpose, field scope, usage alternatives, and prioritization guidance. No output schema exists, but the description sufficiently equips an agent to invoke the tool correctly without further clues.

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?

All parameters have schema descriptions, so the baseline is 3. The description adds meaningful semantic context by clarifying that body content is not searched, which supplements the query parameter description and helps agents avoid misusing the tool.

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 uses a specific verb ('Return'), a clear resource ('normalized email threads'), and explains the grouping behavior ('by subject and participants'). It effectively distinguishes the tool from siblings by explicitly naming search_indexed_emails, get_actionable_threads, and get_inbox_digest.

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?

It states when to use the tool ('Use to view mail as threads rather than individual messages'), when to use alternatives ('use search_indexed_emails to search body content'), and when to prefer two specific siblings for other needs (urgency, executive summary). This is explicit usage guidance.

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