manage_storage

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

With no annotations, the description carries the full burden and does disclose read/write behavior, return shape, origin scoping, and sensitive-data security considerations. It does not explicitly mention side effects such as overwriting an existing key or how a null value is interpreted, which keeps this slightly below a 5.

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 core purpose and uses clearly labeled sections, which helps an agent scan it quickly. There is minor redundancy between 'Tool selection' and 'When not to use' regarding cookies and arbitrary JavaScript, so it is well organized but not maximally tight.

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 description is complete for a simple 4-parameter storage tool despite having no annotations and no output schema: it covers purpose, selection, arguments, return values, security, and origin scoping. The only missing details are edge behaviors such as null handling and overwrite semantics, which are peripheral but could matter in some workflows.

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%, but the 'Args' section compensates by explain key, value, storage, and action, including the enum meanings and conditional value requirement for set. The semantics of a null value and the effect of setting an already-existing key are left to inference, so it is strong but not perfect.

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 opening sentence names the exact operation ('Get or set') and the resource ('a key in localStorage or sessionStorage'), giving a specific verb+resource statement. The tool-selection list immediately distinguishes this tool from siblings like manage_cookies and run_javascript, so there is no ambiguity about what it does.

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 an explicit 'Tool selection' section and a 'When not to use' section, naming alternatives such as manage_cookies, run_javascript, get_content, and get_attributes with clear exclusion conditions. An agent can determine exactly when to invoke this tool versus sibling tools without needing to inspect their schemas.

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