diagnostics

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

With no annotations, the description carries the burden and does add real behavioral context: it explains that CSS/HTML files get index-derived warnings the single-file server cannot see, enumerates the three categories, and discloses an exemption rule for files under WEBNAV_MCP_PUBLIC. It stops short of stating whether the file must be open/indexed or whether the operation is strictly read-only.

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 core action is front-loaded in the first sentence, with the CSS/HTML nuance properly relegated to a follow-up paragraph. Every sentence carries information; only the parenthetical category list is slightly dense for a description.

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?

An output schema exists, so return values need no explanation, and the description adds the scope and edge-case behavior an agent needs. The main remaining gap is the absence of any guidance on when this tool should be chosen over its sibling tools.

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% for the single file_path parameter, so the description must compensate; it only implies a file argument via "for a single file." No format detail (absolute vs workspace-relative path) is given, leaving the parameter underspecified.

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 resource with an explicit scope constraint ("for a single file"), which an agent can act on immediately. It does not explicitly differentiate itself from the overlapping siblings css_var and selector, even though its extra index-derived warnings touch exactly those domains, so sibling differentiation is only 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 implied (call it to get errors/warnings for a file) but there is no explicit when-to-use, no prerequisites, and no routing away from alternatives. Given siblings like css_var and selector that also surface variable/selector information, some statement of when diagnostics is the right pick would have helped.

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