find_old_unread

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

With no annotations provided, the description carries the full burden and does disclose the return shape (message_ids, count, first 50 summaries), which is valuable since there is no output schema. It does not state that the operation is read-only or note that the result is capped at 50 summaries regardless of the `limit` argument, leaving one behavioral ambiguity.

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, front-loaded with the definition and followed by the equivalence note; every clause adds information and nothing is padding.

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 three-parameter, zero-annotation, no-output-schema tool, the definition covers purpose, result shape, and the sibling relationship, which is nearly enough to call it correctly. The remaining gap is the unexplained `limit` parameter and its tension with the 50-summary cap.

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 only partially does: `days` and `folder` are named implicitly through 'older than `days` in a folder', but `limit` is never mentioned and no defaults (30 days, 200 limit, inbox) or folder-name format are given. The 'first 50 summaries' phrase actually muddies what `limit` controls.

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 (unread mail older than `days` in a folder) and immediately positions it against the sibling find_old_messages by declaring it a shorthand for that call with read_state=unread. An agent can tell it apart from find_old_messages and find_bulk_mail without opening a schema.

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?

Gives an intended use case (safest first candidate for a bulk archive) and an explicit equivalence rule versus find_old_messages, so the agent knows when to pick this over the general form. It stops short of stating when NOT to use it, e.g. how it differs from find_bulk_mail or find_unsubscribable.

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