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

With no annotations provided, the description carries full burden but discloses nothing about return format (parsed JSON? raw XML?), error handling (invalid URLs, non-RSS feeds), network timeouts, or whether entries include full text or just summaries.

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?

Extremely concise at 7 words, with no redundancy. However, given the lack of annotations and output schema, this brevity becomes under-specification rather than efficient communication.

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?

Inadequate for a network-fetching tool with no output schema. The description fails to specify what data structure is returned, what feed metadata is included, or how the tool handles malformed feeds, leaving agents uncertain about result handling.

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 has 0% description coverage. While 'from a given URL' hints at the 'url' parameter, the 'limit' parameter (controlling number of entries returned) is completely unmentioned in the description, leaving agents unaware of this pagination control.

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 uses specific verb 'Fetch' and resource 'RSS feed entries', making the core purpose clear. It implicitly distinguishes from sibling 'fetch_article_content' by specifying 'RSS feed entries' (metadata/list) versus article content (full text), though it could explicitly clarify this distinction.

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 provided on when to use this tool versus the sibling 'fetch_article_content', or when to use the 'limit' parameter. No mention of prerequisites like valid RSS feed URLs versus regular web pages.

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