health_trend

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

Annotations already declare the operation read-only, and the description adds what the agent can expect: weekly means, direction, and first-to-most-recent change. It goes beyond the schema by framing output semantics and by implying aggregation over multiple weeks, though it does not address edge cases like insufficient week history.

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 sentences with no filler; the definition is front-loaded and the usage guidance is immediately actionable. Every clause 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?

The description is sufficient for a simple read-only trend tool with an output schema, but it leans on the agent to infer parameter semantics from titles and context. Without schema descriptions or enums, the missing data_type guidance prevents the description from being fully self-contained.

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 0%, so the description must compensate. It explains that the tool tracks 'one metric' (data_type) and implies weeks via 'week-over-week' and 'first week to most recent', but it never defines valid data_type values or precisely how the weeks parameter changes the calculation. Partial compensation, but a real gap remains.

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 states a specific analytical purpose: computing a week-over-week trend for one metric, including weekly means, direction, and change from first to most recent week. This clearly distinguishes it from the daily, readiness, and anomaly siblings by focusing on trend over time rather than a single snapshot.

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 second sentence gives an explicit use case: answer 'is my sleep actually getting worse' rather than reacting to a single bad night. It provides clear contextual guidance but does not name sibling alternatives or state when to prefer a different tool for non-trend questions.

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