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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered structurally. The description adds genuinely useful non-annotation context: the per-call cost of 0.2 points. It does not add anything about rate limits or error conditions, so a 3 is appropriate.

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 tight sentence that front-loads the resource and tacks the cost onto the end. Nothing is wasted; no structural padding.

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 one-parameter read tool with no output schema, the description covers scope, return fields and cost. The only missing piece is pagination/error behavior, which is minor here.

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 coverage is 100% and the single parameter is documented as 'Article id from get_news' with a uuid format, so the schema does the heavy lifting. The description only repeats the provenance, adding no new semantic detail. Baseline 3.

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 and resource ('One article from get_news') and enumerates the content it returns (text, symbols, value, sentiment), so an agent can distinguish it from the sibling get_news list tool. It stops short of explicitly naming the contrast, but the singular wording makes the scope clear.

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?

'from get_news' implies the workflow (call get_news first, then fetch a full article by id), which is usable guidance. There is no explicit when-to-use/when-not statement or alternative named beyond that implication.

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