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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safe read-only nature is covered. The description adds context about return contents ('total record count' and 'capabilities'), which goes slightly beyond annotations but does not disclose potential rate limits, authentication requirements, or response behavior. With annotations present, this is adequate but not rich.

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, well-structured sentence that front-loads the verb and resource, then lists the specific return items. Every word contributes value; there is no filler or repetition. It is appropriately sized for the tool's simplicity.

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?

With one simple parameter and no output schema, the description fully enumerates the return values (fields, geometry type, record count, capabilities), providing enough context for an agent to know what to expect. No additional details about return formatting are necessary since the description covers the core output.

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?

The input schema has 100% coverage for the single 'url' parameter, including an example and description. The description's phrase 'by url' is redundant with the schema. It does add meaning by clarifying the URL identifies a layer and by listing the returned fields, but this is not parameter-specific. Baseline of 3 is appropriate given the schema's completeness.

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 a specific verb ('Get') and resource ('ArcGIS Feature/Map Service layer's schema'), and lists exactly what the tool returns: fields (name + type), geometry type, total record count, and capabilities. This is specific and distinguishes it from sibling tools like query_layer, which likely fetches data rather than schema.

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 implies usage: when you need schema information for an ArcGIS layer, use this tool. However, it does not explicitly mention alternatives or provide exclusions, such as 'for querying features, use query_layer instead.' The context is clear but lacks explicit comparative guidance.

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