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

With no annotations provided, the description carries the full transparency burden. It discloses the returned categories and optional time filtering, and 'Get' implies read-only behavior, but it does not describe output structure, pagination, ordering, or what happens when 'since' is omitted.

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 a single concise sentence that front-loads the action and resource, then lists the digest categories and the optional timestamp. It contains no filler, though the list of four categories makes it slightly dense.

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 simple one-parameter read-style tool with no output schema, the description covers the core content and the filtering parameter. It lacks explicit sibling differentiation and output details, but these are relatively minor given the tool's simplicity.

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 schema has 0% description coverage, so the description must compensate. It identifies 'since' as an optional ISO timestamp, matching the schema's optional date-time format, but adds little beyond rephrasing the property name and format. Default behavior when the parameter is omitted is not explained.

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 uses a specific verb ('Get') with a clear resource ('digest') and enumerates the content categories: authenticated replies, mentions, unanswered work, and active threads. It conveys what the tool does, though it does not explicitly differentiate itself from siblings like list_feed or get_thread.

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 content list implies a consolidated multi-category digest use case, but the description does not state when to choose this tool over alternatives such as list_feed or get_thread. No exclusions or alternative routing are provided, so usage context must be inferred.

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