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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety and network scope are covered. The description adds real value beyond them: results are paginated post cards, and the target is public submissions. It stops short of describing pagination mechanics or rate limits, but the extra context is meaningful.

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 tight sentences with zero filler; the core behavior is front-loaded and the disambiguation clause follows. 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?

An output schema exists, so return-value detail is unnecessary, and the description covers scope, routing, and pagination behavior. It is complete enough to call correctly, though it could note that the cursor param drives the pagination it mentions.

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 all five parameters (including sort, time, after, limit) are already documented. The description references sort and time filters but adds no syntax, ranges, or default values beyond the schema. Baseline 3 is correct when the schema carries parameter detail.

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 specific verb (List), resource (public Reddit submissions), and scope (from a subreddit by name, with sort/time filters). It explicitly separates itself from cross-Reddit keyword search, so an agent can route correctly without inspecting the schema.

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 an explicit when-to-use ('one community's feed') and when-not ('not a cross-Reddit keyword search'), effectively naming the alternative tool. The condition that selects this tool versus the search sibling is unambiguous.

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