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 agent knows it is a safe read operation. The description adds the specific outputs (fields, geometry, record count, capabilities) but no additional behavioral context like auth requirements or rate limits. Given the strong annotation coverage, a 3 is appropriate.

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, compact sentence that front-loads the purpose and clearly enumerates the return values. Every word adds value, with no wasted phrasing. It is exemplary in conciseness while remaining informative.

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 tool with one required parameter, no output schema, and strong annotations (readOnly, idempotent), the description sufficiently covers the tool's behavior and expected outputs. It tells the agent exactly what data it will receive (fields, geometry, count, capabilities), so no critical information is missing.

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 schema covers the single 'url' parameter with a clear description, and the description reiterates 'by url'. Since schema description coverage is 100%, the parameter meaning is fully documented. The description adds no extra syntax or format details beyond what the schema already provides, so the baseline of 3 applies.

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 verb 'get' and the specific resource (ArcGIS Feature/Map Service layer's schema), and enumerates the exact information returned (fields, geometry type, record count, capabilities). This distinguishes it sharply from sibling tools like query_layer and search_within, which focus on data retrieval rather than schema inspection.

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 provides clear context for when to use the tool: when you need a layer's schema by URL. It implicitly distinguishes from alternatives by focusing on schema, not data. However, it does not explicitly state when not to use it or name alternative tools for data queries, which would earn a 5.

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