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

No annotations exist, so the description carries the full load — and it does disclose the key behavioral facts: a per-call price of $0.02 paid via x402, the HTTP method and path, the default behavior (next six hours when times are omitted), and the general shape of the result. It does not cover rate limits, error modes, or reliability guarantees, but the economically relevant facts (cost, auth scheme) are present.

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 the decision the agent is trying to answer, followed by mechanics, defaults, differentiation, and endpoint metadata. No sentence is redundant; even the bracketed HTTP/price/docs block earns its place by carrying cost and provenance info the schema cannot express.

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 two-optional-parameter, output-schema-less tool, the description covers what the tool answers, default windowing, cost, and the general content of the response. Only minor gaps remain (no note on how conditions are summarized, no mention of the sibling point-forecast tool for non-window needs).

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 both 'start' and 'end' are already documented with formats, defaults, and the ≤12h constraint. The description only restates the optionality and the six-hour default, adding no syntax or semantic detail beyond the 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?

States a specific question ('Will it rain in Nashville during your event window'), a specific resource (event-window weather odds for Nashville), and the exact output (rain probability and expected conditions across the window). It also distinguishes itself from the generic sibling by noting 'Same shape as /v1/forecast/window with the Nashville coordinates built in.'

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?

Says explicitly when to use it ('built for scheduling decisions') and how to invoke it with or without parameters ('pass a start and end time (or omit them for the next six hours)'). It implies the city-scoped alternative via the 'Nashville coordinates built in' note, but never names when to prefer the point-forecast sibling over this window tool.

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