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

Annotations already flag destructive=true, non-idempotent, open-world, so the bar is lower, yet the description adds real behavioral facts: repeat calls re-execute the command, output may be truncated as signaled by stdout_truncated/stderr_truncated, and a timed-out MCP request may leave the command running with unrecoverable output. These are exactly the failure modes an agent needs.

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?

Content is front-loaded with purpose and return values, then hazards; every sentence carries distinct information. It runs slightly long and the 'The command is the program or shell expression...' sentence partly duplicates the schema, keeping it from a 5.

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?

For an open-world, destructive, non-idempotent exec tool, the description covers mutation risk, truncation signaling, and timeout semantics, and an output schema exists so return values need no further explanation. Nothing an agent needs to invoke it safely is missing.

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 100%, so name, command, and timeout are already documented with a default; the description largely restates the command parameter and adds no syntax, quoting, or timeout-selection detail beyond the schema. Baseline 3 applies.

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?

States a concrete verb+resource ('Run a shell command on a running Celesto Cloud computer') and names the return payload (stdout, stderr, exit_code), which cleanly separates it from the create/delete/list/info/port/start/stop siblings.

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 phrase 'on a running ... computer' establishes the prerequisite state and 'for work on its guest filesystem and processes' scopes the intended use. It also warns to check state before retrying after a timeout. It stops short of naming an explicit alternative or a when-not condition, but no exec-like sibling exists to route against.

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