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

No annotations are provided, so the description carries full responsibility. It says 'synthesized catch-up' but does not disclose whether the tool is read-only, what it does with messages (e.g., marks as read), or what the output structure is. This is a significant gap for an aggregator that might have side effects.

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 concise sentences: the first states what the tool does, the second gives usage triggers. No filler or repetition, and the most important information is front-loaded.

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 is adequate for a zero-parameter tool: it states the aggregated sources and gives example queries. However, it does not specify what data from each source is included (e.g., all emails, unread only, specific Slack channels) or whether any action is taken beyond display. This leaves an agent to infer scope.

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 tool has zero parameters, so per the rubric the baseline is 4. The description does not need to explain parameter syntax, and the empty schema already fully documents the absence of parameters.

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 the tool produces a synthesized catch-up across inbox, calendar, and Slack, which is a specific resource scope. It distinguishes from single-source siblings like get_inbox or get_calendar, though the verb 'catch-up' is a bit colloquial.

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?

Provides explicit use cases: 'what did I miss' and 'what needs my attention'. It clearly implies when to use the tool, but does not name alternatives or exclusions, so the guideline is clear but not exhaustive.

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