browser_start_tracing

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

Annotations declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false, indicating a non-destructive, idempotent read operation. The description 'Start trace recording' aligns with a non-destructive action but does not disclose details about the side-effect (e.g., tracing might affect performance, start collecting data, or require browser_stop_tracing to stop). It adds little beyond what annotations already provide, so a score of 3 is appropriate.

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 extremely concise at only three words, which is appropriate for a tool with no parameters and a simple purpose. It is front-loaded and efficient, though adding a bit more context on tracing scope would not significantly bloat it.

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?

Given the tool has no parameters, no output schema, and annotations already cover readOnly and openWorld aspects, the minimal description is acceptable but leaves gaps. An agent might need to know if start_tracing must be paired with stop_tracing, or what the recording captures. The description is complete enough for a basic start action but lacks the behavioral context that makes it fully actionable without experimentation.

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 input schema has zero parameters and 100% schema description coverage, so there is nothing to describe. The tool requires no configuration, and the baseline for 0 parameters is 4. The description correctly implies no input is needed, and no additional parameter details are required.

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 'Start trace recording' includes a specific verb and resource, which clearly indicates the tool's basic function. However, among sibling tools like browser_stop_tracing, browser_network_requests, and browser_console_messages, it does not differentiate what kind of tracing is being started (e.g., performance tracing, network tracing, or browser tracing), leaving ambiguity about its exact scope.

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 no guidance on when to use this tool versus alternatives such as browser_network_requests or browser_console_messages, nor does it mention any prerequisites (e.g., whether a page must be loaded or tracing must be stopped before starting). There is no indication of context or exclusions, making it difficult for an agent to decide when to invoke it.

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