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

Annotations already indicate this is a safe, read-only, idempotent operation. The description adds what the tool returns but does not disclose potential runtime behavior, error conditions, or network dependencies. This adds some context beyond annotations but not rich behavioral detail, so a 3 fits.

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 waste. Every part contributes to the meaning, 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?

For a tool with one parameter, no output schema, and simple metadata retrieval, the description is nearly complete. It lists the key return components, but it could mention the output format or potential limitations. Since the description is the only source for return semantics, a slight deduction is warranted.

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?

Schema coverage is 100%, so the baseline is 3. The description mentions 'by url' but adds no additional parameter semantics beyond what the schema already provides. No extra value given, so the baseline score stands.

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 tool's function: retrieving a layer's schema from an ArcGIS Feature/Map Service URL, with specific return items (fields, geometry type, record count, capabilities). It is specific and unambiguous, but it does not explicitly distinguish from sibling tools like query_layer, so it falls short of a 5.

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 usage when one needs schema information for an ArcGIS layer, but it provides no explicit guidance on when to use this tool versus alternatives, nor any exclusions or prerequisites. This is implied rather than stated, so a 3 is appropriate.

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