session_act

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

There are no annotations provided, so the description carries the disclosure burden. The description states it performs a browser action, which implies side effects (navigation, DOM changes), but it does not disclose potential security implications of 'eval' (arbitrary JS execution), rate limits, or what happens on invalid actions or missing sessions.

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?

Single sentence, zero waste, and the action enum is embedded directly in the description, making it instantly scannable. Front-loaded with the verb+resource and immediately enumerating the valid actions.

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?

This is a polymorphic tool with 4 parameters and no annotations or output schema, so it demands more documentation. The description resolves the target polymorphism well but leaves ambiguity about which actions require 'value' versus 'target', error behaviors, and return format. Reasonable for a simple action dispatcher but notable 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 only 50%, but the description compensates by clarifying the polymorphic 'target' parameter meaning across action types (selector for click/fill, URL for goto, key for press, JS expression for eval). This adds meaningful semantics for the most ambiguous polymorphic parameter. However, 'value' and 'session_id' semantics are left to 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 uses a specific verb+resource ('Perform a browser action in a session') and enumerates the supported action types (goto/click/fill/press/eval). It clearly communicates the tool's scope as a browser action executor within a session context, distinguishing it from siblings that start/observe/end sessions.

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 implies usage by listing the action verbs, and the sibling tools (session_start/observe/end) establish the session lifecycle context. However, it does not explicitly state when to use this tool versus alternatives, nor does it mention prerequisites like requiring an active session before executing actions.

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