session_state

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

Annotations already mark the tool as read-only, and the description adds useful behavioral detail: it returns compact text with [N] indexes rather than a full page snapshot. This clarifies what the agent can expect from the response and how it should be used.

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?

Two concise sentences with no filler. The first identifies the resource, the second describes the return format and purpose. Every word contributes to an agent's ability to use the tool correctly.

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?

For a simple read-only tool with one parameter and no output schema, the description covers the essential behavior and return format. It is complete enough for correct invocation, though it could optionally mention what happens when the page is not loaded or has no interactive elements.

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 fully documents the only parameter, session_id, with a 'Session ID' description. The tool description does not add extra meaning about the parameter, but since schema coverage is 100%, no additional compensation is needed. This is the appropriate baseline.

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 states a specific verb ('Get'), a specific resource ('current page state as an indexed list of interactive elements'), and explicitly says the output is for use with click/input tools. This clearly differentiates it from sibling tools like session_navigate or session_scroll.

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 gives clear context for use: it returns indexed elements that are consumed by click/input tools, implying this should be called before interaction. It does not explicitly name alternatives or exclusions, but the purpose is clear enough for an agent to select it appropriately.

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