get_inbox_digest

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

Without annotations, the description must fully disclose behavior. It describes what the tool returns but does not explicitly state whether it is read-only, what side effects syncBefore might have, or any permissions needed. While the three types of threads are listed, there is no mention of data mutability or additional constraints.

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 three sentences long, front-loaded with the purpose, and includes usage guidance concisely. Every sentence adds value with no wasted words.

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?

The description covers purpose, usage, and alternatives effectively. With three simple parameters and no required fields, it provides sufficient context for an agent. However, the absence of an output schema means the description could have elaborated on the return structure, but it is still fairly complete.

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?

The input schema has 100% description coverage, so the description adds no extra meaning beyond what the schema already provides. The parameters (limit, minAgeHours, syncBefore) are adequately described in the schema, meeting the baseline of 3.

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 it returns a 'structured inbox summary' with specific components (unread counts, top actionable threads, overdue threads), and distinguishes itself from sibling get_actionable_threads by noting it's the starting point for an inbox review.

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 explicitly says 'Use as the starting point for an inbox review session' and 'Prefer get_actionable_threads for a deeper, filterable list,' providing clear when-to-use and 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.