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

Although annotations are minimal (readOnlyHint=false, destructiveHint=false), the description clearly indicates a read-only diagnostic operation by stating 'Returns' and clarifies scope with 'the LMCP app upgrading itself, not editing your data.' This adds behavioral context beyond the annotations, disclosing what is inspected without claiming modifications.

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, front-loaded with what the tool does, then provides the usage trigger. Every word contributes to clarity, with no redundancy or irrelevant details.

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 a diagnostics tool with an output schema and one simple optional parameter, the description covers the purpose, the scope (self-upgrade, not data), the specific checks performed, and the situations in which to call it. No additional information is needed for an agent to use it correctly.

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 single parameter 'limit' is fully described in the schema ('Max recent attempts to return (default 10)'), achieving 100% schema coverage. The description mentions 'the last N app-version upgrade attempts,' which aligns with the parameter but adds no additional semantic detail. Baseline 3 is appropriate given schema coverage.

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 uses the specific verb 'Returns' with a clear resource ('LMCP's self-upgrade health') and lists the exact data points (version, attempts, errors, cache writability, stale binaries). It also distinguishes itself by clarifying 'not editing your data' and the scope of self-upgrade, which separates it from sibling tools.

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?

Provides explicit triggers for use: 'when the app's auto-upgrade seems stuck, or to explain why a user is on an old version.' This gives clear context for when to invoke the tool, though it does not explicitly mention alternatives or when not to use it, earning a 4 rather than a 5.

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