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

Annotations cover the safety profile (readOnlyHint=true, openWorldHint=true), and the description goes beyond them by disclosing the hop cap, per-hop report contents, final-URL return, and loop detection. It stops short of stating throttling/rate limits or that private/loopback targets are rejected (that lives only in the schema).

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 well-formed sentence, front-loaded with the action and scope, with the return payload attached compactly. No filler or repetition of the name/title.

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 no output schema, the description carries the burden of describing returns and does so accurately (per-hop fields, final URL, loop flag), and annotations cover the safety profile. Minor gap: it doesn't mention rejection of private/loopback/metadata URLs, which is relevant observable behaviour, though the schema does.

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 50% (only 'url' is described). The description adds the 'max 15 hops' bound and the hop semantics of the walk, which maps to maxHops, but it doesn't clarify the default of 10 or the per-hop latency/status semantics in detail. Baseline 3 for partial coverage plus modest added value.

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 (Follow) and resource (a URL through its redirect chain), plus the exact payload it reports (hop URL, status, latency, Location header, final URL, loop flag). This reads clearly as distinct from siblings like check_url_status or check_ssl, which don't walk the redirect chain.

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 for diagnosing redirect behaviour, but there is no explicit when-to-use, when-not-to-use, or named alternative (e.g. when a simple status check suffices). No prerequisites or error conditions are stated.

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