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

Annotations already declare safe read-only behavior (readOnlyHint, idempotentHint). The description adds valuable context about what specific information is returned (fields, geometry type, count, capabilities), going beyond the annotations without contradicting them.

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 sentence that efficiently front-loads the tool's purpose and output details. Every word adds value; no redundant or unclear phrasing.

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 information tool with one parameter and no output schema, the description covers the key outputs. However, it omits potential issues like invalid URLs or permission requirements, which would enhance completeness.

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?

With 100% schema description coverage, the baseline is 3. The description mentions 'by url' but does not add new semantic details beyond the schema's explanation of the 'url' parameter, which is already adequate.

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', identifies the resource as 'ArcGIS Feature/Map Service layer's schema', and enumerates the exact outputs (fields, geometry type, count, capabilities). This clearly distinguishes it from sibling tools like 'query_layer' which focus on data retrieval.

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 information but does not explicitly state when to use this tool over alternatives (e.g., 'query_layer' for data) or any prerequisites. The context is clear but lacks direct guidance on selection or exclusions.

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