Start Interactive Session

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

Annotations indicate readOnlyHint=false and destructiveHint=false, so the tool modifies state but is non-destructive. The description explains it starts a process that can be interacted with, which aligns with annotations. It discloses return of a session ID and links to child tools, adding context beyond annotations. No contradiction.

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 very concise, structured with Args, Returns, and Examples sections, and front-loaded with the purpose. Every line adds value; no fluff.

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?

Given the tool's moderate complexity (3 params, no output schema), the description covers the purpose, parameters, return value (Session ID), and usage examples. It is complete enough for an agent to decide and invoke correctly.

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%, so baseline is 3. The description adds examples for the command parameter (Python, Node, PowerShell) and clarifies that args and cwd are optional, with cwd being the working directory. This adds practical guidance beyond the schema's 'Arguments' and 'Working directory' descriptions.

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 states it starts an interactive session for subsequent interaction via fc_read_output and fc_send_input, clearly distinguishing from sibling tools like fc_start_process which starts a non-interactive process, and fc_close_session which ends a session.

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 explicitly indicates this is for interactive sessions (Python REPL, Node REPL) and implies it's a prerequisite for fc_read_output and fc_send_input. However, it does not explicitly mention when to NOT use it (e.g., for non-interactive tasks use fc_start_process).

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