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

Beyond the readOnlyHint annotation, the description adds valuable behavioral detail: headlines are sorted newest first, results are metadata-only (headline, date, section, byline, excerpt, canonical URL), and article text is never returned. This gives the agent concrete expectations about response content without contradicting annotations.

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 three sentences with no wasted words: it states the core action, defines the return scope and limitations, and gives concrete use cases. It is front-loaded with the most important information and each sentence earns its place.

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 output schema, full parameter descriptions, and readOnlyHint annotation, the description adds the remaining necessary context: ordering, metadata-only behavior, the follow-up tool, and example queries. It is complete for an agent to select and invoke the tool correctly.

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%, so parameters are already well-documented. The description adds useful semantic grouping by naming the filter dimensions (section, tag, author, date range) that map to the schema properties, reinforcing how the optional filters are intended to be combined.

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: 'List Trend News Agency headlines newest first' and enumerates the optional filters (section, tag, author, date range). It clearly differentiates from trendaz_article_get by stating it returns metadata only and never article text, and it also frames the use case for the list tool.

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 says when to use the tool: to answer 'what has Trend published about X' or 'what did Trend report that week.' It further directs follow-up to trendaz_article_get for full articles, effectively guiding the agent to choose this list tool for headlines and metadata rather than article retrieval.

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