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

Annotations only declare readOnlyHint and openWorldHint; the description adds substantially more: an itemized return shape (title, summary, countries, quorums with support counts), a per-article price of $0.005 with empty pages free, the requirement for a Bearer API key on the connection, and a free tier of 100 calls in 7 days. Those cost and authentication facts are exactly the operational context annotations cannot express.

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, front-loaded with what is returned before the billing and auth constraints. It is dense but nothing is clearly wasted; the long parenthetical about quorums is the only place that could be tightened.

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?

An output schema exists, so return values need no prose, and the description nonetheless covers ordering, filters, pagination, price per record, auth, and the free tier. For a three-parameter read tool with full schema coverage, an agent has everything needed to call it correctly and predict the cost.

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 100%, so the parameters are already fully documented and the baseline is 3. The description's 'filter by country' restates the schema rather than extending it, though the 'most recently active first' ordering and the note that every returned record is billed do add mild interpretation 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?

The description names a specific resource (news articles) and its default ordering (most recently active first), and it enumerates what each article carries. It stops short of distinguishing itself from siblings such as get_article or search_quorums, so an agent must infer the boundary between listing and fetching a single article.

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 supplies context – filter by country, paginate with a cursor, omit the cursor for the newest – which implies when to use it. It never states when to prefer get_article or search_quorums, nor does it flag any exclusions, so the routing decision against siblings is left implicit.

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