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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds that data comes from GDELT's monitoring index and clarifies what 'coverage volume' means (share of all monitored articles vs raw count), but discloses nothing about return shape, granularity, or limits beyond what the schema and output schema already carry.

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 dense sentence that front-loads the core purpose and then qualifies the metrics. It is efficient with no filler, though the parenthetical metric list makes it slightly long.

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?

With an output schema present, full parameter coverage, and annotations carrying the safety profile, the description needs only to convey purpose and scope, which it does. Nothing essential is missing for correct invocation.

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 baseline is 3. The description restates the volume/volume_raw/tone distinction that the metric parameter already documents in full, adding no syntax, defaults, or format guidance beyond the schema.

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: it returns how a query's news coverage has trended over time from GDELT's monitoring index, and enumerates what is measured (volume, raw count, tone). It is clear what the tool produces, but it never names the closest sibling (gdelt_tonechart) or otherwise differentiates itself from the many gdelt_* 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 implies its use by listing metrics but gives no explicit when-to-use guidance, no exclusions, and no pointer to alternatives such as gdelt_search or gdelt_tonechart. An agent must infer the selection rule from the metric list alone.

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