daily_digest

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

readOnlyHint=true already establishes the safe-read profile, and the description adds real behavioral context beyond it: what is included (unread count, summaries), what is deliberately excluded (bodies), and the bounded result size. Missing only notes on truncation/pagination behavior at the limit ceiling.

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 front-loaded sentence gives the whole contract, followed by a tight Args block that is justified given the zero schema coverage. Slight redundancy in restating the schema's default values, but no 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?

With an output schema present, return values need no explanation, and readOnlyHint covers safety. The description supplies purpose, content scope, and all three parameters, leaving only minor gaps such as how the unread count is derived or behavior at the limit boundary.

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 carries the parameter burden and does document all three: folder as target, days as the window, limit as the digest size. It also supplies the 1-100 range that is absent from the schema, though the stated defaults merely duplicate schema values.

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+resource (digest of a folder) and pins down the exact payload: unread count plus recent message summaries with subjects and senders only, no bodies. This implicitly separates it from read_email/list_emails, but no sibling is named explicitly, so it stops short of a 5.

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 'compact digest' framing implies the right moment (a quick overview rather than fetching full messages), but the description never states when to prefer this over list_emails or search_emails, nor any exclusions. Usage is inferable rather than stated.

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