Begin Render Analysis

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

With no annotations, the description carries the full burden. It discloses meaningful behavior: live streaming via react-scan/lite and manual relying on a user-shared DevTools Profiler JSON export, plus the instruction to ask first. However, it does not state whether the tool starts a capture, returns a session ID, or has side effects, which leaves some behavioral uncertainty for a 'begin' action.

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 compact and front-loaded with the core purpose, followed by a scannable two-option breakdown and a single mandatory user-consultation note. No sentence is wasted.

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 one-parameter entry point, the description is nearly complete: it defines both enum values, explains tradeoffs, and mandates user consent. It could be more explicit about what the tool returns or what happens after invocation, but this is a minor gap given the simple schema and clear sibling context.

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 schema already fully documents the enum with descriptions, so the baseline is strong. The description adds helpful selection context: live gives exact rerender causes, source locations, and changeDescription, while manual requires no install and depends on the user exporting a JSON and sharing a file path. This goes beyond the schema's brief enum notes.

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 'Entry point for render profiling,' clearly stating the tool's role and resource. It distinguishes itself from siblings by framing the tool as the initial decision point rather than a load, compare, or summary operation, and it enumerates the live vs manual branches.

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 instructs 'Ask the user which approach they prefer before calling this tool,' a clear precondition for invocation. It also contrasts live (requires npm install, richer data) with manual (no install, less detailed), giving the agent decision criteria. It does not spell out cases where a sibling tool should be used instead, but as the intended entry point this is sufficient.

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