waterfall

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

No annotations, so the description carries the whole burden. It does disclose ordering, the phase legend, and that the critical path falls back to timing alone when initiators/redirects are absent, but it says nothing about truncation via max_rows, width clipping, or what include_secrets does — a security-relevant flag left entirely unexplained.

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 legend and critical-path definition are front-loaded and useful, but the single long run-on sentence mixes output format, phase codes, and a trailing note about the page parameter, making it harder to scan than necessary.

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?

With an output schema present the description need not explain return values, yet it spends most of its length on the visual format while leaving four of five parameters and the secrets-handling behavior unaddressed for a five-parameter HAR tool.

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, and it only covers one of five parameters (page). path, width, max_rows, and especially include_secrets are undocumented; the last is a redaction toggle that an agent could easily mis-set.

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?

States a specific verb and artifact: an ASCII timeline of the page load, one row per request in start order, plus DOMContentLoaded/load markers and a critical path. This is concrete enough to distinguish it from har_overview, though it never explicitly contrasts with siblings like slowest_requests or request_detail.

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?

Implies usage by naming har_overview as the source of page ids and noting page restricts to a single page load, but gives no explicit when-to-use versus when-to-pick-another-sibling guidance, and no exclusions.

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