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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds behavioral context by stating it 'Returns attribute rows (and geometry)' and reveals parameter-style behaviors (SQL-like where, comma-separated out_fields), which is valuable beyond 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 and every part adds value: the action, the source workflow, the key parameters, the return type, and a practical usage tip. No fluff or redundant information.

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 6-parameter tool with no output schema, the description covers the key aspects: what it does, how to use it, and what it returns. It lacks detailed output format (e.g., GeoJSON vs JSON) but provides enough context to select and invoke the tool correctly. The reference to search_datasets helps with the full workflow.

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 schema already fully documents all parameters. The description adds minor clarifications like 'SQL-like' for where and 'comma-separated' for out_fields, but these are redundant with schema descriptions. It does not introduce new meaning beyond what the schema provides, so a baseline of 3 is appropriate.

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 ('Query') and resource ('ArcGIS Feature Service / Map Service layer'), clearly distinguishing this tool from siblings like layer_info (metadata) and search_datasets (dataset discovery). It also outlines key parameters and return type, making the 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 explicitly references 'from search_datasets' indicating the intended workflow, and provides a practical sampling tip ('Use where="1=1" + out_fields="*" to sample'). However, it does not explicitly state when not to use this tool versus alternatives or mention exclusion cases.

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