layer_join

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

Without annotations, the description fully covers behavioral traits: it adds fields to every feature for the rest of the session, explains prefix default behavior to avoid collision, and requires user confirmation. This goes beyond the schema and annotations (none provided).

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 front-loaded with the main purpose, then details parameters. It is appropriately sized for a tool with 5 parameters, though could be slightly more concise. Every sentence adds value, with no wasted words.

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 has 5 parameters (4 required) and an output schema (so return values not needed), the description provides complete context: parameter semantics, behavioral transparency (session persistence, user confirmation), and usage guidance. No gaps remain.

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 0%, so the description must explain parameters. It clarifies 'join_field' is on join layer, 'target_field' on target layer, and 'prefix' defaults to join layer's name if omitted. All 5 parameters are explained, adding meaning 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 joins attributes from another vector layer onto this layer by a shared key field, specifying verbs ('Join another vector layer's attributes'), resources ('layer_id', 'join_layer_id'), and the operation. It distinguishes from sibling tools like attributes_add_field or attributes_calculate by being a join operation.

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 explains when to use the tool (to bring attributes from another layer based on a shared field) and identifies the key fields ('join_field' on join layer, 'target_field' on target layer). It advises confirming with the user first, implying session-persistent modification. However, it does not explicitly state when not to use or mention alternatives.

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