rss_fetch

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

With no annotations, the description carries the full burden and does unusually well: it discloses cost ($0.0025 USDC per call), p99 latency (1500ms), the normalization/HTML-stripping behavior, and the supported feed dialects. Missing only auth/payment mechanics and error behavior, which is a minor gap.

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?

Front-loaded with the core capability, then output shape, then usage, then params/cost/latency in one dense block. Every clause earns its place, though the param recap is redundant with the schema.

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?

No output schema exists, yet the description enumerates the returned item fields (title, link, published_at ISO 8601, summary without HTML, author, guid), so an agent knows exactly what comes back. Cost and latency round out the operational picture for a two-parameter tool.

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 url and limit are already fully documented in the schema; the description's restatement ('url (required), limit (default 20, max 100)') adds no new semantics. Baseline 3 applies since the schema does the heavy lifting.

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?

States a precise verb+resource ('Fetch an RSS 2.0, RSS 1.0 or Atom feed and return normalized JSON items') and enumerates the output fields, which cleanly separates it from siblings such as feed_watch, news_search and webpage_reader.

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?

Gives clear when-to-use context ('monitoring blogs, news sites, GitHub releases, podcasts or any feed URL without writing an XML parser'), which orients the agent well. It does not, however, name an alternative or state when NOT to use it (e.g. feed_watch for recurring monitoring, news_search for keyword discovery).

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