session_list

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

With no annotations, the description carries the full burden of behavioral disclosure. It transparently notes that regular callers see only their own sessions and admins see all, and that include_orphaned defaults to true (as per schema). This is useful behavioral context, though it does not explicitly state read-only nature or potential large result sets.

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 two sentences, direct, and free of unnecessary detail. It effectively communicates the core function and key behavioral nuance without verbosity or structural issues.

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 list tool without an output schema, the description is complete enough. It covers the primary action, visibility rules, and default behavior of the include_orphaned parameter. It omits potential details like return format or error conditions, but these are not critical given the tool's simplicity and lack of an output schema.

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 100% (both parameters have descriptions). The tool description adds meaning by explaining that 'principal' is relevant only for admins and that regular callers are restricted to their own sessions. This goes beyond the schema's 'Admin only: filter by principal' to clarify the behavior for non-admin users.

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 the tool's function: 'List MCP session-store rows'. It distinguishes itself from sibling session tools like session_revoke by focusing on listing. The verb 'List' and resource 'MCP session-store rows' are specific and unambiguous.

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 provides context about visibility (regular vs. admin) but does not explicitly state when to use this tool over alternatives such as session_revoke or user_connection_list. It implies usage for listing sessions but lacks explicit guidance or exclusions.

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