pix_get_event_timing

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

The description adds substantial behavior beyond the annotations: it reads an existing timeline rather than replaying the capture, ranking is dominated by marker scopes, leaves_only changes the ranking granularity, and Windows may start replay automatically while Xbox requires pix_start_analysis with an explicit device_address. It also discloses the returned time_unit. No contradiction with annotations.

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 dense but every sentence earns its place: core behavior, ranking semantics, the alternative tool, cursor behavior, and platform prerequisites are all covered with no filler. Information is front-loaded and logically grouped.

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 output schema exists and the annotations already declare readability and idempotence, the description is complete enough for correct selection and invocation. It covers ranking modes, alternative tools, platform-specific setup, and scalar output units; the few unmentioned parameters are minor and self-explanatory.

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 description coverage is 0%, so the description carries the parameter-semantics burden. It does explain top, leaves_only, cursor_position, and queue-order behavior, but it leaves limit, name_contains, wait_seconds, and timeout_seconds undescribed. Some are self-explanatory from their names, but the description only partially compensates for the complete lack of schema documentation.

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 opens with a precise statement: 'Per-event GPU timing from PIX's own timeline, with start and duration for each.' This clearly names the operation, the resource, the source, and the data shape, and it explicitly contrasts with pix_get_counter_hotspots, making the tool easy to distinguish from its siblings.

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 gives explicit when-to-use guidance: top=N is called the 'cheapest way to find expensive work in a frame,' and pix_get_counter_hotspots is named as the replay-heavy alternative. It also explains mode differences (leaves_only vs queue order) and platform prerequisites (Windows vs Xbox), so an agent knows exactly when and how to invoke it.

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