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

With no annotations, the description carries the full behavioral burden. It does disclose two real traits: the 24h default window and a 5-items-per-section cap, plus that personalization ('for-you rows') depends on me. But it says nothing about ordering, truncation beyond the cap, authentication, or what happens when 'since: seen' is used, leaving core behavior opaque for a multi-parameter read tool.

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?

It is a single sentence with no wasted words, and the scope element is front-loaded. However, the telegraphic parenthetical '(default 24h; unix, 7d, seen)' and the compressed phrase 'for-you rows for me' read as shorthand rather than structure, trading clarity for brevity.

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?

This is a 5-parameter tool with no annotations, no output schema, and only 40% schema description coverage, yet the description is one cramped sentence. Given that the tool apparently assembles and sections content, the description should explain sections, the all vs since interaction, and output format beyond what the enum already says.

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 coverage is only 40%, so the description must compensate, and it partially does: it explains accepted since formats (unix, 7d, seen) with a 24h default, and ties me to the 'for-you rows' output. all and topics remain undocumented in both places ('comma list' is the only hint for topics), so the compensation is incomplete.

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 gestures at the content ('Everything since a time... plus for-you rows for me') but supplies no verb and never says what a 'digest' actually is, so the agent must infer that this is a bundled activity feed. It also gives no differentiation from siblings like explore, list_posts, or my_inbox, which plausibly overlap. Effectively a restatement of the tool's scope rather than a stated purpose.

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 when-to-use, when-not-to-use, or alternative-tool guidance anywhere in the description. The only implied context is the default window ('default 24h'), which is a parameter default, not usage guidance. An agent has no basis for choosing digest over list_posts or explore.

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