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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context: it fetches directly and falls back to a proxy if the source blocks the gateway, which is beyond what annotations provide. It doesn't describe output format, but with no output schema and annotations covering safety, this is a reasonable level of disclosure.

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 sentences with no wasted words. The core purpose is front-loaded, and the proxy fallback and list_feeds guidance are concise additions. Every 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?

For a read-only fetch tool with full schema coverage and annotations covering safety, the description is largely complete. It explains the fetch mechanism, normalization, and proxy fallback. It doesn't mention output format or pagination, but with no output schema and the tool being a straightforward fetch, this is a minor gap.

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 the schema already documents all three parameters (url, limit, query). The description adds the normalization behavior and proxy fallback but doesn't add parameter-specific meaning beyond the schema. Baseline 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 the tool fetches and normalizes RSS/Atom/RDF feeds by URL, which is a specific verb+resource. It also distinguishes itself from siblings by mentioning normalization and the CF-robust fetch behavior, and the sibling list includes read_feed and list_feeds, so the differentiation is useful.

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 to use list_feeds first for curated sources, which provides a clear usage context. It doesn't explicitly state when not to use this tool versus read_feed, but the mention of list_feeds and the general fetch/normalize purpose gives reasonable guidance.

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