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

Annotations already declare the tool as read-only, open-world, idempotent, and non-destructive. The description adds valuable behavioral context beyond this: it returns attribute rows and geometry, supports SQL-like queries, and the sampling tip reveals pagination and field-selection behavior. It does not contradict the annotations.

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 extremely concise: two sentences that front-load the purpose, then provide a useful example. Every word earns its place, with no filler or repetition of schema details.

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 6 parameters, 100% schema coverage, and strong annotations, the description is quite complete. It states the return type (attribute rows and geometry), references the source of the url, and gives a sampling strategy. It could elaborate on pagination or error behavior, but those are covered by the schema and annotations, leaving only minor gaps.

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 coverage is 100%, with all parameters well-described in the input schema. The description does not add new meaning to individual parameters beyond listing them, which is mostly redundant. However, the sampling tip provides a practical use case that adds moderate semantic value, so it stays at the baseline 3.

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 a specific action: 'Query an ArcGIS Feature Service / Map Service layer by its url', which is a distinct verb+resource combination. It also distinguishes from siblings by referencing search_datasets and specifying the output (attribute rows and geometry), 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 provides clear context by noting the url comes from search_datasets, implying the intended workflow. It also offers a practical usage tip (sampling with where="1=1" and out_fields="*"). However, it does not explicitly exclude alternatives like layer_info or search_within, so it lacks formal when-not-to-use guidance.

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