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

Annotations already indicate read-only, open-world, idempotent, and non-destructive behavior, reducing the burden on the description. The description adds value by noting that it 'Returns attribute rows (and geometry)' and providing a sampling tip. This goes 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?

The description is two sentences and efficiently packs core functionality, parameters, return type, and a usage tip. Every clause earns its place with no filler.

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?

The tool is a simple read-only query with a complete schema and clear annotations. The description covers the main behavior, return format, and source of the url. It lacks explicit pagination details (though offset is in schema) and error handling, but for this complexity level it is sufficiently complete.

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% coverage with detailed descriptions for all 6 parameters, so the description does not need to compensate. The description reinforces the parameter names (where, out_fields, order_by, limit, offset) and adds 'SQL-like' context, but provides no additional semantic detail beyond the schema.

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'. It uses a specific verb ('Query'), identifies the resource (Feature/Map Service layer), and distinguishes itself from siblings like layer_info by focusing on data retrieval. The mention of '(from search_datasets)' ties it to a specific workflow.

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 some usage context by indicating the url comes from search_datasets, and offers a practical sampling tip ('Use where="1=1" + out_fields="*" to sample'). However, it does not explicitly state when to use this tool over alternatives like layer_info or 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.