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

With no annotations, the description carries the full burden and does real work: it discloses the response shape (fact, place, time, source_url, age_seconds, stale, confidence), explains what 'stale' means via max_age, and warns that road_closures, power_outages, and burn_ban answers report 'not connected' until sources exist. It does not cover rate limits, auth, or failure behavior for unknown places, which keeps it out of the top band.

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 trigger phrase is front-loaded and the second sentence efficiently enumerates return fields. The middle sentence is a dense run-on with a nested parenthetical about disconnected topics, but no sentence is filler.

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, and the description compensates well by naming every returned field and the staleness flag. Combined with an enum-constrained topic parameter, an agent has enough to call it correctly; only the location-parameter combination rules are left implicit.

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 only 40%, so the description must compensate, and it partially does by tying topic values to source availability and linking staleness to max_age. However, it never explains the lat/lon pair versus the place alternative or that lat/lon must be supplied together, leaving a meaningful gap for the 5-parameter surface.

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?

It uses a specific verb+resource framing ('get cited, time-stamped public facts for anywhere on Earth') and enumerates the covered topics (weather, river levels, floods, earthquakes, disasters, air quality, alerts). The purpose is unmistakable, but the one sibling, ground_truth_sources, is never mentioned, so the agent gets no explicit contrast between the two.

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 opening clause 'Use when you need a current, verifiable real-world fact instead of guessing' is an explicit trigger condition, and the topic list implies the situations it covers. It stops short of when-not-to-use guidance and never routes the agent to or away from ground_truth_sources.

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