create_session

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

With no annotations provided, the description carries the full behavioral burden, and it does disclose two real traits: the session is stateful and both cwd and environment persist. It omits other important behavior, such as whether it returns a session identifier, whether multiple sessions may coexist, resource limits, or how the session is later torn down.

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?

A single compact sentence with the action verb front-loaded and the key behavioral traits (stateful, persistent cwd/environment) packed into the same clause. No filler.

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 session-creation tool with no output schema, the description should explain what the caller receives back, since sibling tools like run_command and destroy_session almost certainly need a session handle. That return-value information is missing, leaving a meaningful gap despite the adequate coverage of the creation semantics.

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 single parameter (cwd) is already fully documented in the schema, including its default of home. The description's phrase 'persistent cwd' loosely reinforces that parameter's role but adds no format or edge-case detail beyond the schema, so the baseline 3 applies.

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 gives a specific verb and resource ('Create a stateful tmux session') plus a scope qualifier ('persistent cwd and environment'), which clearly separates it from destroy_session. It does not, however, distinguish itself from siblings like start_process, which could also be read as creating a session-like execution context.

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 rather than stated: the mention of statefulness and persistence hints that this is the tool to call first when state must survive across commands. There is no explicit when-to-use, no prerequisite statement, and no guidance on choosing between this and start_process.

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