activity

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

Annotations already declare readOnlyHint=true. Description adds behavioral context: cursor-pagination, merged feed, response structure { items[], nextCursor }, and item fields. No contradictions. Adds value beyond annotations.

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?

Concise single paragraph front-loaded with purpose, then details on pagination, item structure, and filters. Every sentence earns its place. Slightly dense but efficient.

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?

Despite no output schema, the description fully specifies the return structure, pagination, filters, and default/max values. Covers all needed context for a read-only feed tool with simple parameters.

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 0%. Description mentions filters (kind, limit) and defaults/max (50, 200) already in schema. Adds meaning for kind enum values ('event' vs 'deliverability') and cursor usage. Does not fully compensate for missing schema descriptions but adds moderate value.

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 is a 'Unified activity feed' merging campaign events and deliverability actions, and distinguishes itself from sibling 'inbox' tool by noting 'Use inbox for replies only.' The specificity of verb and resource is high.

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?

Explicitly instructs when to use this tool vs inbox for replies. Provides filter guidance (kind, limit, cursor). Does not mention other sibling tools like get_dashboard, but the context is sufficient for typical usage.

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