Metis — Scan Nature Briefings

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

With no annotations, the description carries the burden, and it does add some value: 'public archive feed' implies an unauthenticated read-only fetch, which is meaningful behavioral context. It stops short of saying how many editions are returned, whether results are deduplicated against prior scans, or any rate/caching behavior.

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?

A single sentence with no filler, front-loading the verb and resource. Nothing is redundant or buried.

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 tool with an output schema (so return values need no explanation), the description covers what is fetched and from where. The only meaningful gap is sibling disambiguation against nature_briefing, which an agent selecting between overlapping briefing tools would need.

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 no parameter semantics to explain; the empty schema is self-evident. Baseline 4 applies since the description correctly conveys that the call needs no input.

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 ('Fetch') and resource ('latest Nature Briefing editions') plus the source ('public archive feed'), so the action is unambiguous. It does not, however, differentiate itself from the close sibling 'nature_briefing' or 'get_news_briefs', leaving overlap for the agent to resolve.

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 statement of when to use this versus the clearly related siblings (nature_briefing, get_news_briefs, scan_news, check_news_feeds). The word 'latest' hints at recency scoping but no trigger condition or exclusion is given.

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