send_input

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

With no annotations, the description carries the burden. It discloses that text is UTF-8 encoded and written to the process's stdin pipe, adding behavioral detail beyond just 'send input'. It doesn't cover error cases, but the core mechanics are 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 two sentences, immediately states the action, and every sentence adds value. There is no fluff or repetition of schema 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?

The tool is simple with an output schema. The description covers purpose, usage, and behavioral mechanism. It lacks edge-case details (e.g., process not found), but given the simplicity and output schema, it is reasonably complete.

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%, so the description must compensate. It implies that 'stdin' is the text and 'pid' is the target process, but it doesn't explicitly define them. It adds UTF-8 encoding detail for stdin, but leaves pid ambiguous, providing only partial semantics.

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 text to a running process's stdin', specifying the verb and resource. It distinguishes from siblings like send_signal (sends signals) and start/run (creates processes) by focusing on stdin 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?

It explicitly says 'Use this for interactive processes (REPLs, prompts)', providing clear context for when to use. It doesn't mention exclusions or alternatives explicitly, but the context is sufficient to differentiate from siblings.

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