mn_lake_nearby

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

Annotations already declare readOnlyHint=true, indicating safe read-only operation. The description adds behavioral details about the radius parameter (miles, default 5) and states that results are lakes within the radius. No contradictions with annotations; the only omission is what fields the returned lakes include, but this is not critical given the read-only nature.

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 two sentences, front-loaded with the core purpose and immediately followed by the return behavior and radius parameter. Every word earns its place; no fluff or repetition exists.

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 simple 3-parameter tool with complete schema documentation and a readOnlyHint annotation, the description adequately covers the essential behavior: what it does, what it takes, and what it returns (lakes within radius). It does not mention the output format (e.g., lake names/IDs) but this is minor given the low complexity and annotation coverage.

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 descriptions (lat, lon, radius). The description merely reiterates the radius unit (miles) and default (5), which the schema already specifies. No additional semantic meaning is provided beyond the structured schema.

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 uses a specific verb ('Find') and resource ('Minnesota lakes') with an explicit proximity qualifier ('near a latitude/longitude point'). This clearly distinguishes it from sibling tools like mn_lake_search (by name) and mn_lake_detail (by detail retrieval), making the tool's function unambiguous.

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 description clearly states the intended use case: finding lakes near a point, with an adjustable radius in miles. While it doesn't explicitly mention alternatives or exclusions (e.g., when to use mn_lake_search instead), the proximity focus and sibling names provide strong contextual guidance.

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