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

Annotations already declare the tool as read-only, idempotent, and non-destructive. The description adds valuable behavioral context by specifying exactly what schema components are returned (fields + type, geometry type, record count, capabilities), which helps the agent anticipate the tool's output and confirm it is a metadata operation rather than a data query.

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 leads with the action and resource, then lists the return fields. It contains no filler or redundancy, making it highly efficient for an agent to parse.

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 low complexity (one parameter), strong annotations (read-only, open-world, idempotent), and explicit listing of all return values in the description, the tool is fully specified. No output schema is needed because the description enumerates the expected information, and the operation is straightforward and safe.

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 already provides 100% coverage for the single 'url' parameter with a clear description and example. The tool description adds minimal extra semantic value beyond restating that the URL points to a Feature/Map Service layer. With full schema coverage, a baseline score of 3 is appropriate.

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 ('Get') and identifies the exact resource ('ArcGIS Feature/Map Service layer's schema') plus the key outputs (fields, geometry type, record count, capabilities). This clearly distinguishes it from sibling tools like query_layer or search_within, which likely focus on data retrieval rather than schema metadata.

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 when to use this tool by stating it retrieves schema information, but it does not explicitly compare to alternatives or mention exclusions. While the sibling tool names suggest distinctions (e.g., query_layer for data), the description provides no direct guidance on choosing between them.

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