shell_write

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

Beyond the annotations, the description discloses that the operation locks the VM and that stdin can optionally be closed. This is valuable behavioral context that annotations do not provide. No contradiction exists since readOnlyHint=false aligns with the write operation.

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 long, front-loaded with the primary purpose, and every word adds value. The critical unlock instruction is included 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?

The description captures the core function and locking behavior, making it usable for a simple write operation. It does not explain prerequisites like an existing interactive shell session or the output/return behavior, but given moderate complexity and no 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?

With zero schema description coverage, the description compensates by explaining the purpose of text and base64 (content) and eof (closing stdin). However, it fails to mention the session_id parameter or clarify mutual exclusivity between text and base64, leaving gaps for the agent.

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: 'Write UTF-8 text or base64 bytes to an interactive shell' and optionally close stdin. This specific verb+resource+content type distinguishes it from siblings like shell_read (reads) and shell_exec (executes commands).

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 clear context that the VM remains locked and instructs to call vm_unlock when finished, guiding when to invoke this tool in a session. However, it does not explicitly compare against alternatives like shell_exec or shell_start, so it falls short of a perfect 5.

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