pty-mcp

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states the tool 'opens' a session, implying it initiates an interactive terminal, but doesn't describe what happens after opening (e.g., how the session is managed, if it persists, authentication needs, or potential side effects like resource consumption). This leaves significant gaps for a tool that likely involves ongoing processes.

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, efficient sentence that front-loads the core action ('Open a local interactive terminal session') and adds clarifying examples in parentheses. There is no wasted verbiage, making it easy to parse quickly.

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 complexity of session management tools and the lack of annotations and output schema, the description is insufficient. It doesn't explain what the tool returns (e.g., a session ID, output stream), how to interact with the session after creation (hinting at siblings like send_input or read_output), or error conditions. For a tool that likely initiates an interactive process, more context is needed.

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 input schema has 100% description coverage, with the 'command' parameter well-documented in the schema (including default value and examples). The description adds minimal value beyond the schema by listing example commands (bash, python3, node) in parentheses, but doesn't provide additional context like why to choose one command over another or constraints on valid commands.

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 purpose with a specific verb ('Open') and resource ('local interactive terminal session'), and specifies the type of session (bash, python3, node, etc.). It doesn't explicitly differentiate from siblings like create_serial_session or create_ssh_session, but the 'local' qualifier provides some distinction.

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 no guidance on when to use this tool versus alternatives like create_serial_session or create_ssh_session. It mentions the types of sessions (bash, python3, node) but doesn't explain when a local session is preferred over remote or serial sessions, or any prerequisites for usage.

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