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

Annotations already declare readOnlyHint, and the description adds behavioral context by explaining the items are relevance-scored and ranked by momentum. This goes beyond the annotation without contradicting it, though it does not cover pagination or rate limits.

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 two efficient sentences. The first defines the tool's output and ranking, the second provides a sibling comparison. No wasted words, and the most important info is front-loaded.

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 and annotations covering safety, the description adequately explains the tool's purpose and ranking logic. It is complete for a straightforward read-only tool, though it could optionally mention the available topic values.

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% with parameter descriptions for both 'topic' and 'limit'. The description does not add significant extra meaning beyond referring to topic as 'subject', so the 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 what the tool does: retrieves the current AI signal for a topic, defined as recent, relevance-scored items ranked by momentum. It also differentiates from get_region_signal by noting the subject-based slicing, making the purpose distinct and specific.

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 explicitly compares the tool to get_region_signal, indicating when to use this over a geographic alternative. This provides clear context, though it does not mention exclusions or other sibling tools.

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