add_join

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

No annotations are provided, so the description carries the full behavioral burden and does not meet it. It does not say whether the join is virtual or materialized, whether an existing join is replaced, what happens on unmatched records (KEEP_ALL vs KEEP_COMMON is only in the schema), or what errors occur on field mismatch.

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?

A single front-loaded sentence with zero redundancy, and the operative detail (join target, common field) comes first. It is efficient, though the extreme brevity borders on under-specification rather than true conciseness.

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?

An output schema exists so return values need not be explained, but for a six-parameter mutation tool with no annotations the description leaves critical gaps: join semantics, replace/overwrite behavior, and permission or field-type requirements are all absent.

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 100%, so every parameter including keep_all and map_name is already documented in the schema. The phrase 'on a common field' loosely gestures at layer_field/join_field but adds no syntax, format, or constraint detail beyond the schema. Baseline 3 applies.

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?

States a specific verb (join) and both resources (table, layer) plus the keying condition (common field). It is clearly distinguishable from the closest sibling, remove_join, though it does not say which join type is produced.

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?

No when-to-use guidance, no prerequisites (matching field types, existing join behavior), and no reference to alternatives such as remove_join or add_layer. The agent must infer everything about context.

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