list_threads

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

No annotations are provided, so the description carries the full behavioral burden, and it discloses almost nothing: no ordering, result limits, pagination behavior, auth requirements, or whether threads are returned as summaries or full messages. For a list tool that may return unbounded data, the absence of any pagination or limit statement is a real gap.

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?

One sentence, front-loaded with the primary action and resource, with the optional qualifier trailing. Nothing wasted and nothing buried.

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 one-optional-parameter read tool this is close to minimum viable, but with no annotations and no output schema the description leaves return shape, volume, and pagination unaddressed. The agent can call it, but cannot predict what comes back.

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%, so the description must compensate, and it does add meaningful semantics by identifying the single parameter as a Gmail search query. It stops short of explaining the query syntax, whether the filter applies to inbox-only results, or how an empty query behaves.

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?

States a specific verb and resource ("List inbox threads") plus the optional Gmail query filter, so the agent knows exactly what the tool returns conceptually. It does not, however, distinguish itself from the sibling search_messages, which looks like it does something very similar.

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?

"Inbox threads" and "optionally filtered by a Gmail search query" imply a default-browse and an optional-search mode, so usage is inferable. But there is no explicit when-to-use guidance and no mention of the obvious alternative, search_messages, which is the main selection question an agent faces here.

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