jules_get_activityRetrieve a specific activity from a Jules session by providing the session ID and activity ID. Use this to inspect individual task progress or results within a session.
Get a single activity by ID for a Jules session
| Name | Required | Description | Default |
|---|---|---|---|
| session_id | Yes | The Jules session ID | |
| activity_id | Yes | The activity ID |
Changes observed during successful MCP inspections.
v1.3.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and non-destructive behavior, so the description does not need to repeat safety traits. It adds no further behavioral context, such as behavior for missing or invalid IDs or session scoping enforcement, beyond what the schema and annotations convey.
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?
One short sentence conveys the operation, the target resource, and the scoping. There is no filler or redundancy.
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 low-complexity read tool with strong annotations and complete parameter documentation, the description is sufficient for an agent to invoke it. The only minor omission is lack of detail about the returned activity shape or error behavior, but this is a simple get-by-ID operation.
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 description coverage is 100%, so both parameters are documented. The description adds no extra semantics beyond restating that lookup is by activity ID within a Jules session, leaving the schema as the source of parameter meaning.
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 uses a specific verb ('Get'), resource ('activity'), and selection mechanism ('by ID'), and scopes it to a Jules session. This makes the tool's purpose unambiguous and distinguishes it from sibling jules_list_activities, which retrieves multiple activities.
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 phrase 'by ID' and 'for a Jules session' imply the tool should be used when the caller already has an activity ID in a known session. However, it does not explicitly state when not to use it or mention alternatives such as jules_list_activities to first obtain the ID.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.