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

Annotations already cover read-only, open-world, and non-destructive behavior. The description adds materially useful behavior beyond annotations: the list reflects the live sitemap, pagination uses next_offset, and each returned URL still needs independent fetch validation. This sets accurate expectations without contradicting the annotations.

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?

Two tightly packed sentences with no filler. The core action and resource are front-loaded, the pagination detail is immediately useful, and the critical validation caveat is placed at the end without bloating the 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?

For a simple two-parameter list operation, the description covers the key aspects: what is listed, how pagination works, and the necessary follow-up fetch step. There is no output schema, so a more explicit response shape would be slightly better, but 'List ... URLs' and 'paginate with next_offset' give enough for correct invocation.

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 partially does by introducing next_offset as a pagination mechanism that implies how offset should be used. However, it does not explicitly explain the limit/offset relationship or specify bounds; the generic parameter names and defaults carry most of the semantic weight.

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 clearly states a concrete action ('List') and a specific resource ('live sitemap public URLs'), which distinguishes this enumeration operation from the sibling fetch, search, and discovery tools. The pagination note reinforces that the tool returns an iterable list of URLs.

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?

It gives an explicit workflow cue: 'Each page still requires fetch validation' tells the agent that this tool only lists candidates and that successful listing does not imply valid pages. It does not explicitly contrast with search or discovery_status, but the fetch workflow is the key alternative relationship and is clearly stated.

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