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

With no annotations, the description carries the full burden; it usefully discloses a 10-hop cap and the exact per-hop and header data returned, which is real behavioral context. It omits failure behavior (unreachable URL, timeouts, non-redirect targets), whether errors are surfaced as exceptions, and how timing is measured.

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?

One front-loaded sentence that earns its space by naming the hop limit and the returned headers. The trailing header list is somewhat run-on but conveys concrete output detail rather than filler.

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 single-parameter read-only fetch tool with no output schema, the description successfully communicates what comes back (per-hop status/timing plus five header classes) and the hop ceiling. Only error and edge-case handling remain uncovered, which is a minor gap at this complexity level.

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 100% for the single 'url' parameter and the schema already gives a format example. The description adds no constraints on the URL itself (scheme restrictions, domain limits), so it neither compensates nor detracts — baseline 3 applies for a fully documented single-param schema.

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?

Uses a specific verb+resource pairing ('Trace the redirect chain for a URL') and enumerates the data returned per hop, so an agent knows exactly what operation is performed. It doesn't explicitly distinguish itself from siblings like view_as_crawler or test_robots, though the name and phrasing are distinct enough in practice.

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 by the phrase 'redirect chain' — an agent can infer this is for diagnosing redirect paths, but there is no explicit when-to-use, when-not-to-use, or named alternative such as view_as_crawler for broader crawl troubleshooting.

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