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

With no annotations, the description carries the full burden and does well: it discloses output composition, data sources, region scope, and the intentional absence of AI narrative or directional signal. It does not cover latency, failure behavior, or side effects, but for a read-only snapshot tool this is reasonable and informative.

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 description is a single, information-dense passage with a clear front-loaded purpose, followed by structured detail and region enumeration. Every clause adds useful information; nothing is filler or repetition of the schema.

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?

Despite having no output schema, the description sufficiently specifies what the caller should expect: macro indicators with sources, regional headlines, per-region sentiment, a global feed, and the region key set. Combined with the fully documented schema, the tool is contextually complete for invocation decisions.

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 schema already covers 100% of parameters, so the baseline is 3. The description adds value by enumerating the valid region keys and making it clear that sentiment is computed per region, which supplements the schema without redundancy.

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 — 'Get a cross-region global market snapshot' — and enumerates the exact contents: macro indicators, regional headlines, FinBERT sentiment, and a GDELT global feed. It also distinguishes itself by explicitly stating 'No AI narrative, no directional signal — structured real data only', which separates it from sentiment-only or analysis tools.

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 makes the use case clear: use this when you need a cross-region snapshot with macro and sentiment data. It implies the distinction from siblings by emphasizing structured real data and no directional signal, but it does not explicitly name alternatives or state when not to use it, so it stops short of full 5.

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