fact_check

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

With no annotations, the description carries the burden, and it does disclose meaningful behavior: the verdict taxonomy (true|false|misleading|unverified), the presence of reasoning, supporting sources and confidence, and the crucial scope constraint that evidence is limited to current world-news headlines. It stops short of saying anything about latency, cost, or how claims outside news coverage are handled.

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?

The purpose and usage guidance are front-loaded in the first and last sentences, with the return shape placed between them. The return-shape sentence is somewhat redundant against an existing output schema, keeping it from a perfect score, but nothing is padded.

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 detailed return-value documentation is not required, and the description still adds the verdict enum and evidence-base scope. For a single-parameter read-style tool this is nearly complete; only cost/latency expectations and non-news claim behavior are unaddressed.

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 0% and the single `claim` property has no description, so the description must compensate. 'One free-text claim' does establish cardinality (a single claim, not a list or a question) and the expected input type, which is genuine added value, but it says nothing about length limits, formatting, or how to phrase a claim for best results.

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 opens with a specific verb and resource — 'Adjudicate one free-text claim against current world-news headlines' — which tells an agent exactly what the tool produces (a verdict) and against what evidence base. This clearly separates it from siblings like news_analysis, news_brief, detect_deception and answer, which either summarize or analyze rather than adjudicate a single claim.

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?

'Use it to sanity-check a statement before treating it as fact' gives a concrete usage context, so the agent knows the trigger condition. However, it offers no exclusions or named alternatives (nothing says when to prefer news_analysis or detect_deception instead), so it stops short of full routing guidance.

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