session_record_start

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

Beyond the annotations, the description discloses meaningful behavior: it starts background recording of specific user interactions, requires an extension dependency, returns a structured object, and has automatic termination after tab close or four hours. These are exactly the kind of side effects and limits an agent needs to know.

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 compact and front-loaded: it states the core action, lists what is recorded, gives the return shape, and then covers prerequisites and automatic stopping. Every sentence carries useful information with no filler.

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 tool with no required parameters and no output schema, the description covers everything needed to call it correctly: what happens, what is returned, what dependency is required, and when recording ends. This is sufficient context for correct invocation.

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 already documents all three parameters with 100% coverage, so the description does not need to repeat them. It adds value by emphasizing that the sessionId is essential for subsequent recording tools, which helps an agent understand its significance, but this is a minor semantic addition over 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 states a specific action ('Begin recording') and resource ('what happens in a tab'), enumerates the event types captured, and distinguishes itself from siblings like session_record_stop and session_record_events by framing it as the starting point. It leaves no doubt about what the tool 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?

It provides clear context: the T3rnel Browser extension is required, the recording has automatic stop conditions, and the returned sessionId is needed by all other recording tools. It does not explicitly name alternatives or say when not to use it, but the start/stop/event sibling structure makes the use case evident.

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