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

With no annotations present, the description carries the full burden and it does disclose something substantive: an auth-dependent visibility filter (public/canon vs internal/draft gated behind an internal_read scope API key). That is exactly the kind of non-schema behavior an agent needs. Gaps remain — return shape (single record vs list), pagination, and behavior when multiple selectors conflict are unstated.

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 sentences, no filler, and the access-control caveat is front-loaded right after the purpose statement. Every clause carries information an agent needs.

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 four-optional-parameter read tool with no output schema and no annotations, the description covers visibility but not result shape or selector interplay, which is the main source of misuse here. Adequate but with clear gaps an agent must resolve by trial.

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 0% across four parameters, so the description would need to compensate, and it does not: slug, series_id, series_slug, and entity_type are never mentioned or explained. In particular the relationship between slug and series_id/series_slug and the default 'all' for series_slug is undocumented, leaving an agent to guess at selection semantics.

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+resource: retrieving official worldbuilding lore (세계관 설정) for original series. It is clear what the tool returns, but it never contrasts itself with fact-oriented siblings like get_fact or search_facts, so the boundary against those is left to inference.

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?

The only usage condition given is access-level: unauthenticated callers get public/canon, internal_read key holders additionally get internal/draft. There is no guidance on when to call this versus search_facts / get_fact, nor any prerequisite or sequencing advice, so usage is only implied.

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