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

Beyond the readOnlyHint annotation, the description adds meaningful behavioral context: the bash format replays actions against a fresh session on the same server, the jsonl format returns a raw log, and the result is token-free when handed to a shell or cron. This goes well beyond what annotations alone convey.

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 two focused sentences with no filler. It front-loads the core purpose and format names, then adds relevant detail about usage and output. Every clause earns its place.

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 only two parameters, no output schema, and a read-only annotation, this description fully covers the purpose, both formats, default behavior, and expected output. An agent has everything needed to select and invoke it 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 already covers both parameters with detailed descriptions, so the baseline is 3. The description adds extra meaning by enumerating the replayed action types (navigate/click/input/scroll/eval), clarifying the default behavior, and emphasizing the zero-token use case, which helps an agent understand the practical impact of the format parameter.

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 ('Export') and names a concrete resource ('a browser session's recorded action log'). It clearly differentiates this from sibling tools by focusing on exporting the action log rather than performing or managing session actions.

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 clearly explains the two output formats and their intended use cases (runnable replay script vs. raw JSONL log), giving an agent enough context to call it appropriately. It does not explicitly name alternatives or state when not to use it, but the use case is specific and clear.

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