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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds real behavioral value beyond that by stating the sections are the values accepted by smh_headlines, telling the agent how to chain the output. It stops short of describing the return shape, but that is largely covered by the output 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?

Two sentences, zero waste. The identity of the tool is front-loaded and the sibling routing follows immediately, so an agent can stop reading once it has what it needs.

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 zero-parameter, read-only listing with an output schema and full annotation coverage, nothing an agent needs to call it correctly is missing — purpose, downstream use, and the three alternative siblings are all stated.

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?

The tool takes zero parameters, so there is nothing for the description to disambiguate; the baseline of 4 applies. No fabricated or missing parameter guidance is present.

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?

It names a specific verb and resource — 'List Sydney Morning Herald sections' — and immediately ties the output to the sibling that consumes it (smh_headlines). An agent can distinguish it from smh_news, smh_article, and smh_author without inspecting any schema.

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?

The description routes explicitly: use smh_headlines for section stories, smh_news for the general feed, smh_article/smh_author for story and byline details. Both the when and the when-not alternatives are named, leaving nothing to inference.

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