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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. Description adds real behavioral context: default sort/limit, the 100 cap, the interaction between top and time=all, how 'after' paginates, and that empty feeds return not found. No auth/rate-limit detail, but that is minor against the annotation coverage.

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 purpose, then defaults, then error behavior, then sibling routing. Every sentence carries information; no filler.

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 format is not the description's burden. Covers scope, defaults, pagination, error behavior, and differentiation from the sibling tool — nothing an agent needs to call it correctly is missing.

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 per-param descriptions exist and the baseline would be 3. The description adds meaning beyond the schema by supplying defaults (sort=hot, limit=25, top→time=all) and the limit cap, which the schema's plain field descriptions omit.

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 (Browse) and resource (public Reddit posts) plus the exact scope (broad hot/new/rising/top feeds), not subreddit-scoped. It explicitly distinguishes itself from the sibling reddit_subreddit_posts, so an agent can route without opening either 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?

Names the alternative explicitly ('Use reddit_subreddit_posts for trends limited to one subreddit') and gives the condition that selects it. The when-to-use boundary is stated, not inferred.

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