Finnish power grid snapshot

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

No annotations are provided, so the description carries the full behavioral burden. It does convey two useful traits — the data is real-time and 'latest' (freshness semantics), and it is a broad multi-metric aggregation rather than a filtered query. It says nothing about refresh cadence, units, upstream rate limits, caching, or error behavior when the upstream API is unavailable, which matters for a live-data tool.

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?

A single dense sentence with zero filler, front-loaded with the freshness attribute ('Latest real-time') and the geographic scope ('Finnish') before the field list. Every clause names a returned quantity and 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?

With no output schema and no annotations, the description must stand in for both. It does enumerate the metrics, which is the most valuable part, but leaves the response envelope (flat object? nested by metric?), units (MW, Hz, gCO2/kWh), and timestamp field unspecified, and gives no routing to closely related siblings. Adequate to call, not quite sufficient to consume results confidently.

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 tool takes zero parameters, so there is nothing for the description to disambiguate; the baseline of 4 applies. The enumeration of returned metrics helpfully compensates for the absence of any output schema.

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 names a specific resource and scope: a real-time snapshot of Finnish grid metrics from Fingrid, enumerating the exact fields returned (consumption, production, wind, nuclear, hydro, net import, frequency, system state, CO2 factor, non-fossil share). An agent can tell this is the 'current state' reader rather than a time-series or forecast tool. It lacks an explicit verb and doesn't name the sibling it differs from (fingrid_series, fmi_fingrid_nowcast), keeping it below 5.

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?

No when-to-use guidance appears. With siblings such as fingrid_series, fingrid_co2_intensity, fingrid_cheap_hours and fmi_fingrid_nowcast in the same family, the description never says to pick this tool for a single current reading vs. historical series or forecasts. 'Real-time'/'Latest' faintly implies currency, but that is inference, not guidance.

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