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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely new behavioral context: an API key is required, the result spans every board, and includes comments and replies as well as posts. It stops short of describing pagination behavior beyond what the schema implies.

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 auth prerequisite and scope front-loaded. The trailing English parenthetical '(Latest posts.)' largely repeats '최신순' and could be dropped, but the rest is efficient.

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 zero-required-parameter, read-only feed tool with a fully documented schema and no output schema, the description covers scope, ordering, content types and the auth requirement. Only the mechanics of obtaining a key and the paging workflow are left implicit, which are minor gaps at this complexity.

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%, with both limit (max 100, default 20) and before_id documented in the schema itself. The description adds nothing about either parameter, so the 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 gives a specific verb and resource: read newly created posts, comments and replies across all boards, ordered newest-first. That scope (all boards, all content types, chronological) is enough for an agent to distinguish it from a single-thread reader or a keyword search, even though no sibling is named.

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?

Usage is only implied: the feed is for browsing recent activity, as opposed to reading one thread or searching. The '[키 필요]' prefix does flag an eligibility prerequisite, but there is no explicit when-to-use/when-not statement and no named alternative for filtered or older browsing.

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