perf_record

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

The only annotation is readOnlyHint=false, so the description carries most of the burden. It usefully discloses the return payload (GPU ms/frame, frame intervals, FPS, Metal and resident memory) despite there being no output schema, and it implies process launch plus Wine/native dependency. It omits side-effect and cost context: the schema note that export takes about a minute, potential rate/disk implications, and what happens if the program fails to start.

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?

A single front-loaded sentence opening with the verb 'Records', where each clause (what is recorded, the Wine/native distinction, the metrics returned) carries distinct information. No filler or redundancy.

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 7-parameter mutating tool with no output schema, describing the returned metrics is the right call and is done. However, two parameters (prefix, workdir) have no semantics anywhere, and operational caveats such as the roughly one-minute export live only in schema text, so the definition is adequate but incomplete.

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 coverage is 71%, above the midpoint, so the schema does most of the work. The description adds real cross-parameter semantics for `program`/`wine` (an .exe under Wine vs a macOS binary with wine="native") and bounds `seconds`, but `prefix` and `workdir` are documented nowhere, so it does not fully compensate.

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 states a specific verb (records) and resource (a program under Metal System Trace) plus the return content, so an agent knows this is the run-creating tool. It does not, however, name or contrast itself with siblings such as perf_runs or capture_records, leaving that differentiation implicit.

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?

Usage is only implied: an agent can infer this is the tool that produces a recording, and the mention of wine="native" hints at the two execution modes. There is no explicit when-to-use/when-not guidance, no pointer to perf_runs/perf_compare for consuming results, and no stated prerequisites beyond what the schema says.

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