send_control

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

With no annotations, the description fully covers behavioral details: it explains the draining of PTY bytes until quiescence or deadline expiry, and specifies defaults for quiescence timeout and deadline limit. It could mention error handling or return behavior, but overall transparent.

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 concise and well-structured: a brief opening, bullet-point key list, and a paragraph on draining. Every sentence adds value without redundancy.

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 output schema, the description covers sending, draining, and timeout. It lacks explicit mention of return output or error conditions (e.g., invalid key), but overall sufficient for agent invocation.

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 only 33% (only deadline_s documented). The description compensates by enumerating valid key values and their meanings, and clarifying session_id as required from an existing session. deadline_s is elaborated with context about draining.

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 'Send a control character to the terminal,' specifying the verb and resource. It lists the supported keys (c, d, z, l, [, escape) and their effects, distinguishing this tool from siblings like send_text, send_line, etc.

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 requires an existing session via create_session, and constrains deadline_s to at most 300 seconds. While it doesn't explicitly list alternatives or when-not-to-use, the context and sibling tool names imply that this is for control characters only.

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