union_features

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

With no annotations provided, the description carries full burden. It discloses that the tool reads input features and writes output, uses ArcPy Union, and enforces path restrictions. However, it lacks details on performance, input mutability, or error handling, which are important for a spatial operation.

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, front-loaded with the core action, and contains no redundant or tangential information. Every sentence earns its place.

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 complexity (union of polygon layers) and the presence of a detailed schema and output schema, the description covers the essential aspects: what it does, when to use it, and path constraints. Minor improvements could include mentioning attribute behavior more explicitly.

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 description coverage is 0%, so the description must compensate but adds no new parameter information beyond what is already in the schema (e.g., path constraints). It merely restates that paths must be inside allowed roots, offering no additional semantic value.

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 'Overlay two or more polygon feature layers using ArcPy Union and write a new polygon feature class', specifying the verb (overlay), resource (polygon feature layers), and output. It distinguishes from sibling overlay tools by mentioning 'union' and 'retaining attributes from each input', which is unique to union operations.

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 explicit use cases: 'Use this to compare zoning, land-use, administrative, or planning layers'. It gives clear context for when to apply the tool, though it does not explicitly state when not to use it or list alternative tools.

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