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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds genuinely useful context beyond them: NASA provenance, daily cadence/imagery modes, and an explicit cost of $0.005 USDC per call via x402 — a material behavioral fact for budgeting an agent loop.

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?

Three dense sentences with no filler: capability and source first, then use cases, then price. The most decision-relevant facts (what it is, source/date scope) are front-loaded.

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?

There is no output schema, yet the description never says what comes back (image URL, binary, dimensions) — a real gap for an image-producing tool. It also leaves the 0-required-parameter model implicit (agent must infer that either lat/lon or near is needed). Otherwise it covers source, cost, and scope adequately.

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?

With only 57% schema description coverage, the description compensates by clarifying the two locator paths ("centered on a place or coordinates" maps to near vs lat/lon), the date flexibility ("any date"), layer choices (MODIS/VIIRS/night lights), and area sizing. It does not explain pixels vs size_km or their interaction, and lat/lon remain undocumented, so it is not fully compensating.

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 states a specific verb and resource — retrieving a NASA satellite image (daily true-color MODIS/VIIRS or night lights) for a place or coordinates on a date — with the source and layers named. This naturally separates it from nearby siblings like map_static, screenshot, and image_generate without needing to name them.

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?

It gives clear positive usage contexts ("Good for storms, smoke, fires, snow and floods"), which tells the agent when this is the right tool. It stops short of naming when NOT to use it or which sibling to pick instead (e.g. map_static for non-satellite maps), so it does not reach 5.

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