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

Without annotations, the description carries the burden of behavioral disclosure. It reveals that results are ordered most recent first and enumerates the activity types covered, which goes beyond the schema. However, it doesn't state whether this is a read-only operation, how results are paginated, or what the return shape looks like.

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, with the resource and content front-loaded, followed by ordering and use cases. No filler or repetition of schema details. It earns its length.

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 read-oriented list tool with four optional, well-described parameters, the description conveys what the feed contains, its ordering, and when to use it. The lack of an output schema is partially mitigated by the listing of activity types, though pagination and limits are only detailed in the schema.

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 covers all four parameters with descriptions, so the baseline is 3. The description doesn't add parameter-level meaning beyond the schema's own descriptions and the 'with X' use-case phrasing. Since schema coverage is 100%, no deduction is warranted.

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 identifies the tool as an aggregated activity feed covering SMS, calls, emails, notes, deal stage changes, and task completions, with a reverse-chronological order. It is distinct from sibling tools like calls_list or notes_list because it combines multiple activity types, even though it doesn't name them as alternatives. This is a clear statement of purpose, but explicit sibling differentiation is not provided.

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 gives concrete use cases: summarizing 'what happened with X' and building a weekly CRM activity digest. This tells an agent when the tool is appropriate. It doesn't name exclusions or alternatives, but the provided scenarios are sufficient context for typical use.

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