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

Annotations already communicate readOnly, openWorld, and non-destructive behavior. The description adds useful context about the required API scope and the English fallback behavior for untranslated fields, which goes beyond the annotations. However, it does not disclose potential quirks like pagination, sorting, or rate limits, so it provides only partial transparency.

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 extremely concise: two sentences, each earning its place. The purpose is front-loaded, the auth requirement is clearly stated, and the localization nuance is included without padding. No redundant phrases or filler.

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 simple list tool with one optional parameter, full schema coverage, a clear output schema, and annotations that cover safety, the description is nearly sufficient. The only missing context is behavior around pagination or result limits, but given the low complexity and available structured data, the description is adequately complete.

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 optional parameter 'lang' is fully documented in the schema, including its enum values and default. The description merely restates the fallback behavior already in the schema ('English is the fallback for untranslated fields'), adding no new semantic value. Baseline of 3 is appropriate.

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 clearly states the verb 'List' and resource 'newsrooms', making the tool's basic purpose obvious. It does not explicitly differentiate from siblings like sources_get or sources_activity, but the 'list' vs 'get'/'activity' distinction is implied by the name and title.

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 mentions a prerequisite (requires sources API scope) but provides no guidance on when to use this tool over alternatives such as sources_get, sources_activity, or search_list. There is no mention of filtering, pagination, or use cases, leaving the agent to infer when this list endpoint is appropriate.

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