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

Annotations already provide readOnly, idempotent, openWorld, and non-destructive hints. The description adds valuable context about the actual return payload (fields, geometry type, record count, capabilities), which helps the agent anticipate output. There is no contradiction with annotations, and the added detail goes beyond the basic hints.

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, tightly packed sentence that front-loads the purpose and enumerates the exact outputs. There is zero waste; every word contributes to understanding the tool's function.

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 tool's simplicity (one parameter, no output schema), the description is highly complete. It explains both what the tool does and what it returns, covering the essential aspects an agent needs. Annotations cover safety, so no further behavioral disclosure is needed.

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 already provides a thorough description of the 'url' parameter, including an example and the expected format ('.../FeatureServer/0'). The description only repeats 'by url' without adding new semantic information. With 100% schema coverage, the 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 names the exact resource: an ArcGIS Feature/Map Service layer's schema. It lists concrete returned elements (fields with name+type, geometry type, total record count, capabilities), which clearly distinguishes it from the sibling tool 'query_layer' that presumably fetches data.

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 context is clear: this tool is for retrieving schema/metadata, not data rows. However, it does not explicitly name alternatives or state when NOT to use this tool. Since the use case is obvious (schema retrieval), it earns a 4 rather than a 5.

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