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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the description need not repeat that. It adds useful behavioral context: the required API scope and the English fallback for untranslated fields. These go beyond the annotations and help the agent understand auth and language behavior.

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 concise, two short sentences with no redundancy. The main concept is front-loaded, and the additional requirements are stated efficiently. It is appropriately sized for the tool's simplicity.

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?

Given the tool has a rich schema (5 params, 100% coverage) and an output schema, the description is minimal but sufficient. It adds auth scope and language fallback, but does not explicitly state the return type (list of trending stories) or the ranking mechanism, though these are implied by the name and schema. It is adequate but leaves some context to inference.

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 all five parameters are fully documented in the schema. The description adds no additional meaning about parameters, such as how they interact or typical usage. It meets the baseline for a fully-covered schema but does not enhance parameter understanding.

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 'Stories picking up speed' conveys the concept of trending stories but is metaphorical and does not explicitly state that this tool returns a list of trending stories. It is distinguishable from siblings like stories_list by the 'picking up speed' hint, but the purpose is not stated with a clear verb+resource pattern. The name helps, but the description alone is vague.

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?

No guidance is given on when to use this tool versus alternatives. It mentions a prerequisite (stories API scope) but does not explain when to choose trending_list over stories_list or other siblings. There is no mention of use cases, exclusions, or alternatives.

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