session_list

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

With no annotations, the description carries the full transparency burden. It makes the read-only list behavior clear and discloses the returned attributes, but it does not mention ordering, pagination, or other behavioral details such as whether closed sessions are excluded.

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 a single, well-structured sentence that starts with the action and immediately delivers the key semantic information. Every word is meaningful, with no redundancy or boilerplate.

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?

As a straightforward zero-parameter list tool with no output schema, the description is largely complete: it identifies the resource and the returned fields. A brief note on ordering or cell-level access would improve completeness, but the current information is sufficient for basic selection.

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 tool has zero parameters, which matches the baseline of 4 for tools without parameters. The description needs to explain parameter-level semantics, and it does so implicitly by defining the scope of the returned list.

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 ('List') plus a specific resource ('open sessions') and even names the returned fields: kind, cell count, and creation time. This clearly communicates what the tool does and distinguishes it from sibling tools like session_list_cells, which operate on cells rather than sessions.

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 clear context for when to use this tool—when you need a list of open sessions and their basic metadata. However, it does not explicitly state when not to use it or point to alternatives like session_list_cells for cell-level information.

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