List sessions

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

Annotations already disclose read-only, idempotent, open-world, and non-destructive behavior, so the description's burden is lower. The description adds the default non-archived behavior and the includeArchived/filter interaction, but much of this is also present in the schema property descriptions. It contributes useful context but does not add substantial behavioral detail beyond the annotations and schema.

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 concise sentences with no wasted words. It front-loads the primary purpose, then gives the default behavior, then lays out the two options for modifying archival filtering. Every sentence serves a clear decision-relevant purpose.

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-only list tool, the description plus annotations and full schema coverage are largely sufficient: purpose, filtering behavior, and parameter semantics are all covered. The main gap is that no output schema exists and the description does not describe the shape or ordering of returned sessions, but 'List sessions' plus the tool title makes the return expectation reasonably clear.

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%, and the schema already documents filter, pageSize, pageToken, and includeArchived with examples and override behavior. The description only repeats the includeArchived and filter concepts without adding new parameter-level meaning. Baseline 3 is appropriate because the schema carries the parameter documentation burden.

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?

Description states a specific verb ('List') and resource ('Jules sessions'), making the tool's core function immediately clear. It also clarifies the default scope (non-archived) which adds precision. It does not explicitly distinguish itself from jules_get_session or jules_list_sources, but the plural resource and list semantics make that distinction reasonably inferable.

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 clear usage context for the main decision: by default non-archived sessions are returned, includeArchived=true changes that, and a raw AIP-160 filter overrides the default. It does not mention alternatives like jules_get_session for retrieving a single session, so the guidance is scoped to filter options rather than sibling tool selection.

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