Daily insulin totals (Glooko per-day figures)

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

Annotations declare readOnlyHint=true, and the description adds meaningful behavioral context: the most recent day may be flagged provisional if still today and not finalised, and all dates are wall-clock (device-local) days. It also clarifies that the bolus figure is pre-aggregated by Glooko, which is a behavioral nuance beyond the annotation. It does not describe pagination or error behavior, but for a read-only data retrieval tool this is solid.

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 well-structured: a one-sentence summary, a usage paragraph, a provisional-data note, and a return-shape paragraph. Every sentence earns its place, and the most important scoping information is front-loaded. It is detailed but not bloated.

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 read-only tool with two fully documented parameters and no output schema, the description covers the return shape, the source, the provisional flag, and the wall-clock semantics. It also addresses the key distinction from sibling tools. Nothing an agent needs to call 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 coverage is 100%, so the schema already documents both parameters thoroughly. The description adds value by explaining the wall-clock semantics and the 'Z' format artifact, which is critical for correct usage. It also clarifies that timestamps returned are likewise wall-clock. This goes beyond the schema's own caveats and reinforces the key semantic trap.

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 verb and resource: it returns Glooko's own per-day insulin totals (basal, bolus, combined total) plus a window aggregate. It clearly distinguishes itself from sibling tools by noting that bolus here is Glooko's pre-aggregated daily figure, while other tools use event-level aggregation. This is a precise, non-tautological definition.

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 says when to use this tool: when you want device-reported daily totals, e.g., a day-by-day basal/bolus table or total daily dose per day. It also names alternatives (get_diabetes_summary, get_trend) for event-aggregated bolus, and notes that basal is only available from Glooko, so this tool and those share the same basal source. This is strong routing guidance.

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