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

Annotations already provide read-only, idempotent, open-world, and non-destructive hints, lowering the bar. The description adds value by specifying exactly what information is retrieved (fields, geometry type, record count, capabilities), going beyond the annotations to clarify the tool's output behavior. This is useful additional context for an agent.

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 written sentence with no wasted words. It front-loads the core action ('Get an ArcGIS Feature/Map Service layer's schema') and then enumerates the return components clearly. Every word contributes to understanding the tool's purpose.

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?

With no output schema, the description effectively communicates the return value (schema fields, geometry type, record count, capabilities). It is sufficient for a simple 1-parameter tool with strong annotations. It lacks explicit usage caveats (e.g., error handling), but the provided context is adequate for typical use.

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 description coverage is 100% with the 'url' parameter already described in detail (including an example). The description merely repeats 'by url' without adding extra semantic meaning beyond the schema's own description, so the baseline 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'), names a clear resource ('an ArcGIS Feature/Map Service layer's schema'), and lists concrete outputs (fields, geometry type, record count, capabilities). It clearly distinguishes from siblings like 'query_layer' by focusing on schema metadata rather than data queries.

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 for schema inspection but does not explicitly state when to use this tool vs alternatives or provide exclusions. The phrase 'Get an ArcGIS Feature/Map Service layer's schema' gives clear context, but no explicit 'when-not-to-use' or alternative tool references are mentioned.

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