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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is clear. The description adds beyond annotations by stating that the tool returns attribute rows and geometry, and provides a sampling tip. This enriches the agent's understanding of behavior without contradicting 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 two sentences, front-loaded with the core purpose and syntax, and concludes with a practical tip. Every sentence adds value, with no filler or repetition of schema details. It is efficiently structured for quick comprehension.

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 lack of an output schema, the description appropriately mentions that the tool returns attribute rows and geometry. It also links to search_datasets for obtaining the url, covers the key parameters, and gives a sampling pattern. With rich annotations and full schema coverage, this is sufficient for an agent to select and invoke the tool correctly.

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%, so the baseline is 3. The description adds semantic value by explaining the SQL-like nature of the 'where' parameter and by suggesting a specific combination (where="1=1" + out_fields="*") for sampling. This goes beyond the schema descriptions, justifying a 4.

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: 'Query an ArcGIS Feature Service / Map Service layer by its url'. The specific verb 'query' and the resource type distinguish it from sibling tools like search_datasets (for finding datasets) and layer_info (for metadata). It also mentions returning attribute rows and geometry, which further clarifies the purpose.

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 a workflow by saying 'from search_datasets', indicating the url should come from that tool. It also gives a concrete usage tip for sampling (where="1=1" + out_fields="*"). However, it does not explicitly state when not to use this tool or name alternatives, so it falls short of a 5.

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