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

Annotations already declare readOnly, idempotent, non-destructive and openWorld=false, so the safety profile is covered. The description adds genuinely new behavioral context beyond that: whole-world result ordering for air_quality (worst readings first) and weather (hottest), which an agent cannot derive from the schema or annotations.

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 opening is front-loaded and readable, but roughly half the text restates the layer enum already present in the schema's layer description, which is wasted space. The trailing sentence about world-wide ordering is useful but tacked on rather than integrated.

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?

All five parameters are documented in the schema, annotations cover the safety profile, and the description explains the layer taxonomy. With no output schema, the description could say more about the shape of returned pins/readings, but for a self-explanatory read tool this is close to complete.

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 every parameter (date, layer, limit, place, radius_km) is already documented, and the baseline is 3. The description reinforces that 'place' can be omitted for the whole world, but that is already in the schema, and the ordering note is a result behavior rather than parameter semantics.

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 the resource (Mappit's live map layers) and enumerates the concrete layer values with their data sources (USGS, NASA FIRMS, Open-Meteo), so an agent knows exactly what this tool returns. It does not explicitly differentiate itself from siblings like whats_happening or get_statistic, which also surface live data, so it falls short of a 5.

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?

Usage is only implied through the layer enumeration; there is no explicit 'use this when' statement and no alternative sibling is named or contrasted. The reader must infer that this is the tool for map-layer data versus the digest/story/statistic tools.

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