get_daily_briefing

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

With no annotations, the description carries the full behavioral burden, and it does proactively disclose the read-only, non-mutating nature clearly. However, it omits other traits an agent needs: required permissions, whether results are cached/generated fresh, and any rate or scope behavior on the account.

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 tight sentences, front-loaded with the core action and scoped by the read-only guarantee. No filler, though the second sentence largely restates the first's 'read-only' framing.

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 4-parameter generator with no output schema and no annotations, the description gives source scope and a safety guarantee but never says what the briefing actually returns or how the limit/day parameters shape it. Adequate but with concrete gaps.

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 only 25% (just 'account'), so the description must compensate, but it does not. It loosely gestures at the inbox and follow-up sources but never clarifies mailbox, unread_limit (default 10, max 50), or follow_up_days (default 7, max 30), leaving three of four parameters unexplained.

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 ('Create a read-only daily briefing') and enumerates its three data sources (one inbox, local approval queue, saved follow-up dates). It is distinguishable as a composite/aggregate tool, though it never explicitly names which sibling tools it overlaps with (list_approval_queue, list_follow_up_radar).

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?

There is no guidance on when to use this versus the sibling listers it aggregates (list_approval_queue, list_follow_up_radar, list_messages). The only constraint given is a negative one ('never drafts, sends, or changes email'), with no when-to-use or alternatives stated.

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