query_history

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

Annotations already indicate readOnlyHint and openWorldHint. The description adds valuable behavioral details: events are recorded only during specific operations and retained for 30 days, which goes beyond the annotations. No contradiction.

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 brief and efficient: two sentences that capture purpose, usage, and data availability. It is front-loaded with the main verb and resource, then provides essential context. Every sentence earns its place.

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 that an output schema exists, the description does not need to detail return values. It sufficiently covers behavior (data source, retention) and usage context (event types). For a query tool, this is comprehensive.

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 coverage is 100%, so baseline is 3. The description does not add significant new meaning about individual parameters beyond what the schema provides, but the overall context (e.g., event recording conditions) indirectly informs parameter use.

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 'Query local event history' and provides concrete example questions ('Did the door open today?', 'When did the washing machine finish?'), making the tool's purpose immediately understandable. It differentiates from siblings like get_device_status by focusing on historical events.

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 explains when data is available (during 'mijia-home-mcp watch' runtime and get_home_changes calls) and retention (30 days), guiding appropriate use. It does not explicitly state when not to use, but the context is clear enough.

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