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

With no annotations, the description carries the full burden and does meaningfully: it discloses the data source, unit conventions, that incomplete days are flagged and never filled, and the licensing/tier constraints. It omits auth mechanics (how a Pro key is supplied), rate limits, and error behavior.

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?

Information-dense but front-loaded, leading with what the tool returns before tier and licensing details. The parenthetical '(no key or free key)' is slightly awkward and the free/Pro theme recurs, but every sentence carries real content.

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 6-parameter read tool with no output schema and no annotations, the description supplies the source, coverage windows, unit, licensing and data-integrity behavior an agent needs to call it correctly. Return-shape and pagination details are the only notable gaps.

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 coverage is 83%, so the schema already documents start/end/city/station/limit/offset. The description reinforces the date-range semantics and the Pro-key history limit but adds little syntax or format detail beyond what the schema already provides; baseline 3 is appropriate.

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 precise resource (daily high/low temperature and cooling/heating degree days, base 65°F) with an explicit source (NOAA NCEI) and the exact station scope (8 named Texas airports). An agent instantly knows what this returns and can distinguish it from the electricity/market siblings.

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?

Clear access-tier context: free keys get the most recent 30 days, a Pro key unlocks full history, and commercial use requires Pro. There is no weather sibling to route against, so explicit alternatives are unnecessary, but it stops short of the full when/when-not statement.

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