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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false. The description adds useful behavioral context beyond this: it states that the tool 'Returns attribute rows (and geometry)' and offers a practical usage tip. 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 three sentences long, front-loaded with the primary purpose, and every sentence contributes either parameter context, return information, or a practical tip. It is concise with zero redundant wording.

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 moderate complexity, the combination of a fully described schema, comprehensive annotations, and a description that covers return type and usage patterns makes it complete. Even without an output schema, the description adequately explains what the tool returns and how to invoke it.

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 all six parameters, so the baseline is 3. The description adds extra semantic value by labeling the 'where' clause as 'SQL-like' and providing a canonical sampling example (where="1=1" + out_fields="*"), which helps users understand parameter usage beyond the schema definitions.

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 function with a specific verb and resource: 'Query an ArcGIS Feature Service / Map Service layer by its url.' It also references 'from search_datasets', which distinguishes it from sibling tools like layer_info and search_within, making its purpose unambiguous.

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 after search_datasets and provides a concrete sampling pattern ('Use where="1=1" + out_fields="*"'), giving clear context. However, it does not explicitly state when not to use it or how it differs from alternative sibling tools like search_within, so it lacks explicit exclusions.

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