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

With no annotations, the description carries the full behavioral burden. 'Runs the same code the tool page runs' adds almost nothing actionable — it does not say whether a live network fetch occurs, whether redirects (including JS/meta-refresh) are followed, whether there are timeouts or rate limits, or what errors look like.

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?

Three short sentences, front-loaded with the core action, with no padding. The final 'Scope: check' fragment is mildly redundant but not harmful.

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?

This is a simple one-parameter tool, so expectations are modest, but with no output schema the description should indicate what comes back (final URL only, redirect chain, status codes). It also omits any distinction from the redirect/expand siblings, leaving a real gap for selection.

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?

There is a single parameter with 100% schema description coverage ('Full URL including scheme'), so the schema already does the work. The description adds no extra meaning about URL handling or formatting beyond what the schema states.

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 gives a specific verb and resource ('Resolve a URL to its final target'), which is more precise than a bare name restatement. However, it never distinguishes itself from the very similar siblings check_redirects and check_url_expand, so an agent must guess which one to pick.

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?

There is no when-to-use guidance and no mention of alternatives, despite at least two overlapping siblings (check_redirects, check_url_expand). The fragment 'Scope: check' hints at a category but does not tell the agent when this tool is the right choice.

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