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

Annotations only cover the safety profile (readOnly/idempotent/non-destructive). The description adds substantial behavior the annotations cannot: the MAX_RANGE_POINTS truncation rule with remediation advice, the default 3-day window when from/to are omitted, the raw-vs-grid tradeoff, and the UTC-only contract for both inputs and returned timestamps.

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?

Front-loaded with purpose, then required params, then the resolution mechanics, then response shape. It is dense with little filler, though resolution/default details partially duplicate the schema and the trailing EN keyword list is SEO padding rather than guidance.

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?

No output schema exists, yet the description fully describes the return object ({count, resolution, points[{ts, value_float, value_str, lat, lng}]}), including the geo-sensor case where value_* is null. Combined with defaults, limits and time semantics, nothing needed 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 description coverage is already 100%, so baseline is 3. The description goes beyond the schema by specifying that object_udid and series_key must be sourced from onto_object_show (series_keys), and by reinforcing the practical resolution choice (300 for a Tagesroute) and the raw-by-default behavior.

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?

States a specific verb and resource with its exact scope: "VERLAUF einer Zeitreihe lesen: die Punkte zwischen zwei Zeitpunkten". The scope clause (between two timestamps) inherently separates it from the sibling onto_series_last, so an agent can route correctly without opening either schema.

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?

Gives strong user-intent triggering ("wie war der Verlauf / die Tagesroute / die Messkurve") and tells the agent where the required identifiers come from (onto_object_show: series_keys). It never explicitly names the alternative tool to prefer for the latest value only (onto_series_last), so the when-not half of the guidance is left to inference.

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