down

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

No annotations are provided, so the description must carry the behavioral burden; it discloses a significant constraint not present in the schema — that only session-started runtimes are eligible and human-started ones are never affected. It does not address reversibility, graceful shutdown, or failure behavior for an unknown runtime, which a destructive operation would ideally cover.

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?

Two short sentences, zero padding, with the core purpose and the exclusion rule front-loaded. Nothing is redundant with the schema text.

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?

An output schema exists, so return values need no explanation, and the description supplies purpose, scope, and the key usage exclusion. For a destructive, confirmation-gated operation it could do slightly more on error/permission behavior, but nothing essential to invoking it correctly 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 both parameters (runtime and confirm) are already documented in the schema, including the 'as returned by up' provenance and the confirm=true requirement. The description adds only the session-scope constraint on the runtime, which maps to the schema baseline rather than new syntax.

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 specific verb (Stop) and resource (a runtime) and immediately narrows scope to runtimes 'this MCP session started with up.' The cryptic tool name 'down' is fully disambiguated, and the session-scope qualifier separates it from siblings like stop, restart, and run_delete.

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?

Explicitly states the 'when' (stopping a runtime started via up in this session) and the 'when-not' (runtimes started by a person are never stopped from here). It references the counterpart tool 'up' but never names an alternative for the excluded case, so routing for person-started runtimes is left implicit.

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