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

Annotations already declare readOnlyHint=true and destructiveHint=false, covering the safety profile. The description adds useful context by specifying what the caller receives (fields, geometry type, record count, capabilities), which goes beyond the annotations without contradicting them. No additional behavioral traits (e.g., rate limits) are disclosed, but they are not expected for a simple read-only schema tool.

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, focused sentence that immediately states the verb and resource, then lists the specific schema components. There is no redundant or filler content, making it highly concise and well-structured.

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 documented parameter, no output schema, and clear annotations, the description fully covers what the tool does and what it returns. It completely explains the tool's purpose and output given the simplicity of the tool.

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 covers the only parameter (url) with a clear description and example, achieving 100% coverage. The tool description does not add meaning beyond the schema for the parameter itself; it focuses on the output. 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 states a clear, specific verb ('Get') and resource ('ArcGIS Feature/Map Service layer's schema'), and enumerates the returned components (fields, geometry type, record count, capabilities). This clearly distinguishes it from sibling tools like query_layer, which likely fetch 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 purpose statement implicitly defines when to use this tool: whenever you need layer schema, not data. While it doesn't explicitly name alternatives or exclusions, the context is unambiguous given the description and sibling tool names. It lacks an explicit 'use when' or 'use instead' statement, so it doesn't earn a 5.

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