get_user_activity

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

With no annotations, the description carries the full burden and does real work: it discloses the pagination mechanism (submissions plus next_after) and, importantly, warns that returned titles/bodies/comments are untrusted user-generated text to be treated as data, not instructions. It omits auth requirements and rate-limit behavior, so it isn't exhaustive.

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?

Three tight sentences, front-loaded with purpose, then return/pagination shape, then the safety caveat. No filler or restated boilerplate.

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?

There is no output schema and no annotations, so the description must cover behavior; it does cover return shape, pagination, and the untrusted-content caveat. It stops short of describing rate limits or auth, but for a read-only fetch tool the essentials are present.

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 username, sort, and after are already documented, including the cursor semantics. The description's mention of next_after largely restates the schema's 'after' description rather than adding new syntax or constraints. 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?

States a specific verb and resource ('Get a Reddit user's recent posts') and immediately scopes it ('for source-vetting'), which cleanly separates it from get_subreddit_posts, search_reddit, and get_post by resource. An agent can pick this tool without opening 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 use case ('is this poster a bot/spammer'), which tells the agent when this tool is the right choice. It doesn't name the sibling alternatives or state when NOT to use it, so it stops short of full routing guidance.

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