pty-mcp

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

With no annotations provided, the description carries full burden. It discloses key behavioral traits: it waits for output to settle, can timeout, and returns a completion status. However, it doesn't mention side effects (e.g., if it modifies session state), error handling, or performance characteristics like rate limits.

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 extremely concise—two sentences that are front-loaded with the core action and follow with critical return behavior. Every word earns its place, with no redundant or vague phrasing.

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 no annotations, no output schema, and low schema coverage, the description is minimally adequate. It covers the basic operation and return value, but lacks details on error cases, session state implications, or how output is structured, which are important for a tool interacting with sessions.

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 33% (only 'timeout_ms' has a description). The description adds no explicit parameter semantics beyond what's implied by the tool's purpose. It mentions 'command' indirectly via 'input' but doesn't clarify parameter roles or constraints, leaving gaps for 'input' and 'session_id'.

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 ('Send a command and wait for output to settle') and resource (implied session input/output). It distinguishes from siblings like 'read_output' by specifying it sends input and waits, but doesn't explicitly differentiate from 'send_control' which might be for control signals rather than command input.

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 you want to send a command and wait for completion, with a fallback to 'read_output' if timeout occurs. However, it doesn't specify when to use this versus 'send_control' or other session tools, nor does it mention prerequisites like needing an active session.

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