get_update_command

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

Annotations provide readOnlyHint=true, destructiveHint=false, idempotentHint=true, openWorldHint=true. The description reinforces these with 'READ-ONLY', 'Pure local introspection + cache read; no RPC, no fresh network call', and 'Never throws'. It also explains the heuristic nature, caching behavior, and potential caveats, adding significant context beyond annotations.

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 longer than minimal but well-structured: it starts with purpose, then lists return fields using backticks, and ends with agent behavior. Every sentence adds necessary context. Could be slightly more concise, but it remains clear and scannable.

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?

With no output schema, the description completely covers return values, their meanings, and how they are derived (heuristics + cache). It also includes agent behavior, edge cases (unknown installPath, unresolved version check), and operational constraints (no network call). This makes the tool fully understandable without needing external documentation.

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 input schema has zero parameters with 100% coverage, so baseline is 3. However, the description adds substantial value by detailing the output fields (current, latest, updateAvailable, installPath, command, restartHint, note) and their semantics, which compensates for the lack of parameter explanations.

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 starts with 'READ-ONLY — return the recommended upgrade flow for the running install path', which is a specific verb-resource pair. It then explains exactly what the tool does: combines heuristics and cached state to return upgrade command, and distinguishes itself by clarifying it's a pure local read with no network call.

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 explicitly states when to call the tool: 'when the user asks to upgrade, when the VAULTPILOT NOTICE — Update available block appears and the user wants to act on it, or when the user asks how do I update vaultpilot-mcp'. It also provides agent behavior instructions: 'Surface command to the user verbatim — do not execute it autonomously' and what to do if installPath is unknown.

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