pty-mcp

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

No annotations are provided, so the description carries full burden. It states the tool reads output without sending input, which hints at read-only behavior, but doesn't disclose other traits like whether it requires specific permissions, how it handles errors, if it returns real-time or cached data, or any rate limits. This leaves significant gaps in understanding the tool's behavior.

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 directly states the tool's purpose without any fluff. It is front-loaded and appropriately sized, making it easy to understand quickly. Every word earns its place by conveying essential information.

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 (a read operation with a required parameter), lack of annotations, no output schema, and low schema coverage, the description is incomplete. It doesn't explain what the output looks like, how to interpret it, or any prerequisites for using the tool. This leaves the agent with insufficient context to use the tool effectively.

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 description coverage is 0%, with one parameter (session_id) undocumented in the schema. The description adds no information about this parameter, such as what session_id represents or how to obtain it. Since there's only one parameter, the baseline is higher, but the description fails to compensate for the lack of schema details, providing minimal value beyond the 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 action ('read') and target ('current screen output') with a specific constraint ('without sending any input'). It distinguishes from siblings like send_input or send_control by emphasizing passive observation. However, it doesn't explicitly differentiate from list_sessions or list_remote_sessions, which might also involve reading session data.

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 implies usage when needing to view screen output without interacting, suggesting it's for monitoring rather than control. However, it lacks explicit guidance on when to use this versus alternatives like list_sessions (which might provide session metadata) or when not to use it (e.g., if input is required). The context is clear but not comprehensive.

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