send_keys

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

With no annotations, the description carries the full burden. It discloses supported key tokens, how regular text is handled, and the return type, but omits behavioral details such as whether an existing session is required, what happens on failure, or whether it blocks waiting for output. This is a moderate disclosure.

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: a clear purpose sentence, a useful list of key tokens, an illustrative example, and a concise args listing. Every sentence adds value, making it appropriately sized and front-loaded.

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?

The description covers the core behavior and parameters, and with an output schema present, the return statement is sufficient. However, it does not clarify how the tool interacts with sessions (e.g., whether it requires an existing session or can create one), which is relevant given sibling tools like list_sessions. This gap lowers completeness.

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%, but the description compensates well: it explains each parameter (host, keys, username, port), provides examples for keys, and specifies that username and port are optional. This adds meaningful semantic value beyond the raw 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 uses a specific verb ('Send') with a clear resource ('special keys or key sequences to a session') and lists supported key tokens, distinguishing it from siblings like send_input by focusing on special key handling.

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 by detailing special key tokens and mixing text, but does not explicitly compare with sibling tools like send_input or send_input_by_session, nor state when not to use it. There is no explicit alternative guidance, so it falls short of a higher score.

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