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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, covering the safety profile. The description adds value by detailing exactly what the tool returns (fields, geometry type, record count, capabilities). It does not mention network/auth/error behavior, but the annotations lower the burden and the read-only nature is well covered.

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, information-dense sentence that front-loads the action ('Get') and resource ('ArcGIS Feature/Map Service layer's schema'). Every word contributes meaning; no filler or redundancy.

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 simple one-parameter, read-only tool, the description fully covers what it does and what it returns. The input schema covers the parameter, annotations cover safety, and the description explains the output components since there is no output schema. Complete and self-sufficient.

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 has 100% description coverage for the single 'url' parameter, including an example. The tool description adds no additional parameter-level semantics beyond restating that it is a URL. With high schema coverage, 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 clearly states the tool's purpose: 'Get an ArcGIS Feature/Map Service layer's schema by url' and enumerates the specific output fields (fields, geometry type, total record count, capabilities). This is a specific verb+resource combination that distinguishes it from siblings like query_layer which would 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 description provides clear context: use this when you need schema information for a layer URL. It does not explicitly name alternatives or exclusions, but the mention of 'schema' makes it distinct from data-querying tools. No explicit when-not-to-use guidance is given, so it falls 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.