bash

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

With no annotations, the description carries the full burden of behavioral disclosure. It explicitly states that state persists across calls (including directory and env vars), that there is no internet access, and that state persists across discussions. It also discloses constraints and recommendations (avoid large output, run background commands) and suggests a specific technique (sed). This is rich, transparent behavior description beyond the basic action.

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, starting with the core purpose and then presenting bullet-pointed usage tips. It has a slight redundancy: 'State is persistent across command calls and discussions with the user' repeats the initial statement about persistence. However, the overall structure is clear and front-loads the most important information without wasting words.

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 the tool's flexibility and only one parameter, the description covers key operational aspects: persistence, network capabilities, output handling, and background execution. It does not mention exit codes or the format of command output, which could be useful, but for a general shell tool the guidance is sufficient for an agent to use it effectively. The absence of an output schema is partially mitigated by the description's behavioral notes.

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?

The schema covers the single 'command' parameter fully, providing its type and a note about relative paths. The description adds value by offering practical guidance on how to construct commands: using sed for line inspection, avoiding excessive output, and handling long-running processes. This enriches the parameter's usage semantics beyond the schema, earning a score above the baseline of 3.

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 'Run commands in a persistent shell,' specifying the verb (run), resource (commands in a shell), and a key behavioral trait (persistence). It distinguishes itself from the sibling tool str_replace_editor, which is for file editing, making it a precise and unambiguous purpose.

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 for usage: it mentions the shell is persistent, warns about no internet access, advises avoiding large output, and recommends running long-lived commands in the background. Though it doesn't explicitly compare with alternatives, the context and tips implicitly guide appropriate use. It doesn't state when not to use this tool, but the guidance is practical and specific.

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