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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the description adds genuine context beyond them: it enumerates the returned fields and clarifies that feed subscriptions are managed by the owner in the app, so this endpoint cannot add feeds. It omits ordering and pagination behavior, which is the main remaining 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?

Two compact sentences with the resource front-loaded and the usage hint second. The first sentence mildly conflates 'the feeds followed' with 'the items they brought', but no sentence is wasted.

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 single-parameter read-only list tool with no output schema, the description covers what is returned (fields), where it comes from, and that feed management is out of band. An agent has enough to call it correctly without further context.

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?

Only one optional parameter (limit, default 20) and schema description coverage is 100%, so the schema carries the load. The description adds nothing about limit, result ordering, or whether the newest items come first, so baseline 3 applies.

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 states the specific resource (RSS/Atom feed items from followed feeds, surfaced on the ideas board) and enumerates returned fields (title, summary, link). It is clear what the tool returns, though the verb is implicit and the overlap with sibling list_ideas is not addressed.

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?

'Good material for posts: summarise or comment on an item and link to it' implies a use case (content inspiration) but gives no when-not conditions and never names an alternative among list_ideas, get_idea, or search_mentions. Usage is inferred rather than stated.

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