PTY MCP Server

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

The description adds valuable behavioral context beyond annotations: it explains that sessions remain in the list after exit until cleaned up with pty_kill, and it details the tool's role in monitoring (e.g., 'Check the status and output line count'). However, it does not fully address the annotations' hints (e.g., destructiveHint: true is not explained, and openWorldHint: true implications are unclear). No contradiction with annotations exists, but more could be said about the destructive and non-idempotent aspects.

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 well-structured and front-loaded with a clear purpose statement, followed by a bulleted list of use cases and additional context. Every sentence earns its place by providing specific guidance or clarifying behavior, with no redundant or vague information. It is appropriately sized for the tool's complexity.

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 complexity (no parameters, but involves session management) and lack of output schema, the description is mostly complete: it explains what the tool does, when to use it, and key behaviors like session persistence. However, it could better address the annotations (e.g., why destructiveHint is true) and provide more detail on output format or error handling, leaving minor gaps in full contextual coverage.

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?

With 0 parameters and 100% schema description coverage, the baseline is high. The description adds no parameter-specific information (as there are none), but it effectively compensates by explaining the tool's output semantics (e.g., session IDs, status, output line count), which is valuable given the lack of an output schema. This enhances understanding beyond the empty input schema.

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 specific verbs ('Lists all PTY sessions') and distinguishes it from siblings by specifying it includes 'active and exited' sessions. It explicitly mentions the resource (PTY sessions) and scope (all, including exited ones), making it highly specific and differentiated from other pty_* tools.

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 explicit usage guidelines with a bulleted list of when to use this tool (e.g., 'See all running and exited PTY sessions', 'Get session IDs for use with other pty_* tools'), and it implicitly distinguishes from alternatives by not overlapping with functions like pty_kill, pty_read, etc. It also clarifies that sessions remain listed until cleaned up with pty_kill, guiding when not to use this for cleanup.

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