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

Annotations already declare readOnly, idempotent, non-destructive behavior, so the bar is lower, yet the description adds real value: it discloses the one-hour cache, alphabetical ordering, and the exact fields returned per entity (including npc_hp being null for resources). It does not mention rate limits or what happens at page boundaries, keeping it from a 5.

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?

Short, front-loaded paragraph with the entity scope first and supporting detail after. The opening clause 'World entities: animals, NPCs, resource nodes' repeats the title verbatim, which is mild redundancy, but otherwise every sentence carries information.

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?

With no output schema, the description appropriately compensates by enumerating the returned fields (slug, display_name, is_npc, npc_hp, icon_url) and noting the cache lifetime. Pagination semantics are left to the schema, which documents them fully, so the definition is essentially complete for an agent to call it correctly.

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 kind, page, search, and per_page all documented in the schema including an enum explanation. The description adds no parameter-level detail beyond what the schema already supplies, 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?

States a specific verb-and-resource combination ('One page of world entities') and clarifies scope ('anything not tied to one monument'), which distinguishes it from the single-entity sibling get_world_entity. It falls short of a 5 because the search/filter capability implied by the tool name is not surfaced as the primary purpose.

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 phrase 'one page of world entities ... alphabetical' suggests listing/browsing, and the scoping note hints it is not for monument-bound entities. There is no explicit guidance on when to prefer this over search_items, list_monuments, or get_world_entity.

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