send_keys

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 explains that keys are sent without appending Enter, covers tmux notation, and advises using get_snapshot() to see results. It doesn't detail potential side effects (e.g., if the session is not open), but for a keystroke-sending tool this is reasonably transparent and goes beyond the schema.

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-organized: a one-sentence purpose, a bulleted list of use cases, a notation explanation, a result-checking tip, and an Args section. It is a bit longer than strictly necessary, but every part contributes useful information. It is front-loaded with the core behavior, so an agent can grasp it 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?

An output schema is present, so return values don't need to be explained. The description covers the tool's purpose, usage patterns, key notation, and parameter formats. It even suggests the appropriate follow-up action (get_snapshot to see the result). For a tool of this complexity, the description is thorough and leaves no major gaps for an agent to guess about.

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 coverage is 0%, so the description must compensate. The 'Args' section provides clear meanings for both parameters: session_id format is 'user@host-<id>' and keys uses tmux notation. It even includes examples like 'C-c' and 'C-c Enter', which adds significant value beyond the bare string types in 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 opens with a specific verb and resource: 'Send raw keystrokes to a session without appending Enter.' This clearly distinguishes it from sibling send_command, which presumably sends full commands with Enter. The direct statement of behavior leaves no ambiguity about what the tool does.

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 use cases: interrupting commands, sending EOF, interactive input, and special keys. It gives concrete examples and explains tmux key notation. While it doesn't explicitly say 'when not to use' or name an alternative tool like send_command, the 'without appending Enter' phrasing implies the distinction and the context is sufficient for an agent to select this tool appropriately.

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