list_threads

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

No annotations are present, so the description carries the full burden. It discloses pagination behavior and required filters but omits potential side effects, authentication needs, or rate limits. Response structure is partially described.

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 extremely efficient: two-sentence overview, a listed return format, critical usage note, and clear parameter descriptions. No redundant phrases, front-loaded with purpose.

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 an output schema exists (not shown but indicated), the description appropriately mentions return fields. Pagination and required filters are covered. Minor gap: not explicitly handling order behavior with cursor, but overall sufficient for a list tool.

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 description coverage is 0%, but the description compensates by explaining all 5 parameters: purpose (inbox_id recommended, domain_id filtering, range for limit, pagination cursor, order direction with defaults). Adds meaning beyond the schema's property titles.

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 lists email threads with pagination and describes the returned fields. It distinguishes itself from siblings like search_threads by focusing on general listing with filtering by inbox/domain.

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 explains that at least one of inbox_id or domain_id must be provided and how pagination works with next_cursor. However, it does not explicitly contrast with sibling tools like search_threads or provide when-not-to-use guidance.

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