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

Annotations already disclose read-only, idempotent, and non-destructive behavior, covering the safety profile. The description adds the specific return fields but does not mention potential performance costs of counting records or any network/auth prerequisites, so the added behavioral context is limited.

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?

A single, front-loaded sentence that clearly states the action and resource, then compactly lists all the information returned. Every element earns its place with no 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?

Given the tool's simplicity (one parameter), rich annotations, and no output schema, the description sufficiently conveys what the agent should expect: schema fields, geometry type, record count, and capabilities. It does not explain error handling, but that is not critical for this straightforward metadata lookup.

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 description for the sole url parameter is 100% comprehensive, including an example, so the baseline is 3. The tool description merely echoes 'by url' without adding any new semantic detail beyond the schema.

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 clearly identifies the resource as an ArcGIS Feature/Map Service layer's schema. It enumerates the exact outputs (fields, geometry type, total record count, capabilities), making it distinct from sibling tools like query_layer that likely handle feature 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 description clearly implies this tool is for schema/metadata retrieval when you have a layer URL. It does not explicitly name alternatives or exclusions, but the context is strong enough (schema vs. data query) to guide selection within the sibling toolset.

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