arc_set_storage

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

With no annotations, the description must disclose behavior. It only states the basic action of setting a value, without mentioning key overwrite behavior, scope to a specific tab, or the fact that objects are JSON-stringified (though that is in the schema). Important behavioral traits are missing.

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 a single sentence that concisely captures the tool's purpose with no unnecessary words. It is front-loaded and efficient.

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 4 parameters (2 required) and no output schema or annotations, the description is adequate but incomplete. It lacks details on overwrite behavior, scope, and error handling, which would help the agent use the tool correctly.

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 schema has 100% description coverage for all four parameters, so the description does not need to add parameter info. However, the description adds no extra semantic context beyond the schema, such as typical use cases for storage_type or tab_index. Baseline score 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 clearly states the tool sets a value in localStorage or sessionStorage. The verb-resource combination is specific and distinguishes it from sibling tools like arc_get_storage_item (get) and arc_remove_storage_item (remove).

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 no guidance on when to use this tool versus alternatives like arc_set_cookie for cookies or arc_clear_storage for clearing. It does not specify any prerequisites or constraints, leaving the agent to infer usage from the name and schema.

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