Solar History

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

Annotations already declare readOnly/idempotent/non-destructive, so the description's job is added context, and it delivers: data provenance (IONIS, GFZ Potsdam, NOAA SWPC) and a 2000-2026 coverage window that tells the agent which dates are valid. It stops short of noting range limits, rate limits, or gaps in the historical record.

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 tight sentences: what it returns and its source first, the sibling routing last. Every clause carries information, and nothing is buried.

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?

Complete enough for a read-only historical query: coverage window, sources, and return fields are stated, and an output schema exists so return shapes need no explanation. Minor gap is whether resolution='3hour' applies to all indices or only Kp, and whether the date range has a maximum span.

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 100%, so all three parameters (start_date, end_date, resolution) are already documented with formats and the daily/3hour option. The description adds no syntax or constraint detail beyond that, so the baseline 3 applies.

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?

Names a specific verb+resource (query historical solar indices) and enumerates exactly what data comes back (SFI, SSN, Kp, Ap; solar flux, sunspot number, geomagnetic indices). It also scopes itself against the live-data sibling, so an agent can distinguish it 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?

Explicitly states the use condition (a date range of historical data) and the exclusion (live/current conditions belong to the other tool). The only flaw is that the named alternative, 'solar-mcp's solar_conditions', does not match the actual sibling name current_conditions, which could cause a lookup miss even though the intent is unambiguous.

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