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

Annotations already declare this as a safe, read-only, idempotent operation. The description adds context about what information will be returned and the scope (schema by URL), going beyond the annotations by specifying the output contents (fields, geometry type, count, capabilities). No contradictions with annotations are present.

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, well-structured sentence that front-loads the core action ('Get an ArcGIS Feature/Map Service layer's schema') and immediately lists the key output elements. Every word is informative, with no redundancy or filler.

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 a single parameter and no output schema, the description sufficiently explains the return content by listing the four main pieces of information. It could mention potential edge cases (e.g., invalid URL) or explicitly note that it does not return features, but the current scope is adequate for a straightforward metadata tool.

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 fully documents the 'url' parameter with a clear description and example. The tool description only says 'by url,' which adds no new semantic meaning beyond the schema. The baseline of 3 applies due to high schema coverage.

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') with a clear resource ('ArcGIS Feature/Map Service layer's schema') and enumerates the exact information returned (fields, geometry type, record count, capabilities). This clearly differentiates it from sibling tools like query_layer, which would focus on data retrieval rather than schema metadata.

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 when to use the tool (when you need schema information from a layer URL), but it does not explicitly mention alternatives or exclusions. It would benefit from a note like 'use query_layer for actual feature data,' but the implied usage is clear enough for a minimally viable score.

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