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

Beyond the readOnlyHint and openWorldHint annotations, the description discloses important behavioral facts: the exact payment amount, the network (Base), the payTo address, and the attribution requirement. It also names the underlying public data source (Open-Meteo), giving the agent a clear picture of side effects and obligations.

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 extremely compact and front-loaded: payment, purpose, location syntax, units, attribution, related tools, and payment address all appear in a few short phrases. Every clause adds information; there is no filler or redundancy.

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 simple read-only weather tool, the description covers the essentials: how to pay, where to send payment, how to specify location, and the units. The main gap is that it does not describe the return shape or what happens if neither q nor lat/lon is supplied, though both are inferable.

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 input schema already covers all four parameters at 100% coverage. The description adds useful meaning by clarifying the relationship between q, lat, and lon ('and/or') and reiterating the units choices (metric|us). This goes slightly beyond the schema's individual descriptions.

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 clearly states the resource ('current weather via public Open-Meteo') and the input patterns ('q= place and/or lat=&lon='). 'wx' is uniquely identifiable among the sibling tools as a weather lookup, and the phrase 'Complements /geo /tz' further orients it relative to nearby tools.

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 gives clear invocation context: how to specify a location, the optional units, and the payment/attribution requirements. It names related sibling tools (/geo /tz) but does not explicitly state when to prefer wx over them or when not to use it, so it stops short of a 5.

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