perf_sched_map

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

With no annotations provided, the description takes on the full burden of behavioral disclosure. It discloses the output format ('ASCII grid with CPUs as rows and time as columns'), a key prerequisite ('Requires: perf sched record'), and parameter effects (compact, cpus, pids, coloring). While it does not mention failure modes or side effects, the read-only nature is implied by the map output, making it reasonably transparent.

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 front-loaded with the core purpose, followed by usage guidance, key parameters, output format, and prerequisite. It is slightly longer than necessary due to repeating parameter names that already exist in the schema, but each sentence serves a purpose and the structure is logical and scannable.

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's complexity (15 parameters) and the presence of an output schema (so return values need not be explained), the description covers the essential aspects: purpose, usage, output, and prerequisite. It does not explain all parameters, but the schema covers those. The description is complete enough for an agent to decide whether to use it and to understand its core behavior.

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 already has 100% description coverage for all 15 parameters. The description adds modest value by explaining 'compact: one-character-per-task view' and grouping related parameters (color_pids/color_cpus), but most of the parameter semantics are already present in the schema. It does not meaningfully deepen understanding of parameters like symfs, vmlinux, or verbose beyond the schema descriptions.

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 opening sentence 'ASCII CPU activity map showing which task ran on which CPU at each time slice' names the specific verb (map), resource (CPU activity), and output format, clearly distinguishing it from sibling tools like perf_sched_latency or perf_sched_timehist. It explains the visual output and use case for scheduling patterns, CPU affinity, and load imbalance.

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 explicitly states 'Use this for a visual overview of scheduling patterns, CPU affinity issues, and load imbalance,' giving a clear when-to-use context. It does not explicitly mention when not to use it or name alternative tools, but the visual-overview framing strongly implies differentiation from statistical or script-based siblings.

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