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

Annotations already declare read-only, non-destructive, idempotent, and open-world behavior. The description adds valuable behavioral details beyond annotations: mentions multiple results ranked by proximity, accuracy type, and source – crucial context for agent decision-making without contradicting any annotation.

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 description is a single, dense sentence that efficiently communicates the tool's purpose, scope, and outputs without filler. It is front-loaded with the core action and all information is relevant.

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?

Given the output schema exists, the description need not detail return values. It covers the primary purpose, geographic scope, and behavior (multiple results, proximity ranked). It is complete for a simple reverse geocode tool, though no mention of rate limits or API keys (not expected in general).

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?

Input schema covers 100% of parameters with full descriptions. The description does not add any information beyond what the schema already provides for lat, lon, and limit. Baseline 3 is appropriate since schema does the heavy lifting.

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 clearly states the action ('reverse geocode'), the resource ('latitude/longitude to a US or Canada address'), and specifies the output (formatted address, parsed components, accuracy, source). It effectively distinguishes from the sibling 'address.geocodio.geocode' by using 'reverse' and explicitly limiting scope to US/Canada.

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?

While the description clearly implies usage when you have coordinates and need a US/Canada address, it does not explicitly contrasts with sibling reverse-geocoding tools like 'geo.address.reverse' or provide when-not-to-use guidance. However, the geographic scope gives strong selection criteria.

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