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

The description adds specific behavioral details beyond annotations, detailing the exact schema components returned. It doesn't contradict the readOnlyHint and idempotentHint annotations, reinforcing the safe, read-only nature of the operation.

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, front-loaded sentence that conveys all essential information without redundancy. Every word earns its place.

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 simple one-parameter tool with rich annotations, the description adequately covers the return content (schema fields, geometry type, record count, capabilities) and leaves no major gaps. The lack of an output schema is compensated by the explicit listing of returned information.

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 only parameter 'url' is fully described in the schema with format and example. The description's 'by url' adds no additional semantic information beyond what the schema already provides, so baseline 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 the specific verb 'Get' and identifies the resource as an ArcGIS layer's schema, listing the exact information returned (fields, geometry type, record count, capabilities). This clearly distinguishes it from siblings like query_layer.

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 implies the tool is for retrieving schema information rather than querying data, providing clear context for when to use it. However, it doesn't explicitly name alternatives or exclusions, so it stops short of a 5.

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