list_activities

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

With no annotations, the description must carry the transparency burden. It discloses that the tool returns indexed activities/logs rather than raw S3 data, which is helpful. However, it does not explicitly state that it is a read-only operation, define 'recent', or mention any permission requirements or 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?

The description is concise and front-loaded with purpose. The param docs are structured clearly with no filler or redundant repetition of the schema. Every sentence earns its place.

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 two-parameter list tool with an output schema present, the description covers the essential purpose and parameter behavior. It could mention the time window for 'recent' or sorting order, but these are minor gaps given the output schema likely defines the return shape.

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 description explicitly explains both parameters: 'limit' as maximum activities to list (with default 10) and 'offset' for pagination. This adds meaningful semantics beyond the bare schema, which only provides types and defaults. Since schema description coverage is 0%, the description fully compensates.

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 specifies the action ('List'), the resource ('recent S3 activities/logs'), and the scope ('indexed in ObjectLens'). This distinguishes it from siblings like list_buckets and list_bucket_objects, which target different resources.

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?

Usage is implied by the resource and tool name, but there is no explicit guidance on when to use this tool versus alternatives or any exclusions. The description does not mention that it only handles indexed activities, which could be a useful clarifier.

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