pix_get_counter_hotspots

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

Annotations already mark the tool as read-only, idempotent, and non-destructive. The description adds meaningful behavioral context beyond those annotations: the automatic selection of the capture's best per-event duration counter when nothing is specified. It does not mention refresh or caching behavior, but the annotation coverage lowers the burden.

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 sentences with no filler. The main purpose is front-loaded, and the second sentence adds a useful and non-obvious default behavior for omitted parameters.

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 complex tool with 10 parameters and zero schema descriptions, this description is not complete enough for correct advanced invocation. An agent can use the default capture_id-only path, but has no guidance on filtering, ordering, timeouts, or counter selection beyond the automatic default. The output schema covers return values, but parameter semantics remain underspecified.

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 must compensate for the 10 parameters. It only clarifies the counter parameter's omission behavior; parameters such as counter_groups, counter_regexes, refresh, ascending, and queue_name receive no semantic explanation.

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 specific verb ('Rank') and resource ('events by a counter') and states the goal ('find the most expensive GPU work'). It is clear, but it does not explicitly differentiate from sibling analysis tools such as pix_collect_counters or pix_get_timing_summary.

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 gives clear context by identifying this as the 'usual starting point for a performance investigation' and explains the default behavior when no counter is specified. It does not provide explicit when-not-to-use guidance or name alternative sibling tools.

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