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

Annotations already establish read-only, idempotent, non-destructive, closed-world behavior, and the description adds genuinely new context: the result is a lightweight one-line summary plus id, filtering is partial-match on name OR alias, and results are paginated. It stops short of saying what happens by default (e.g., whether all characters are returned when no name is given) or total counts.

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 short sentences, front-loaded with what the tool returns before covering filtering and paging. No filler or restated title.

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?

No output schema exists, and the description compensates by describing the returned fields; annotations cover the safety profile. Remaining gaps are small but real for a 4-parameter tool at 0% schema coverage: default paging values and the required nature of world_id are unstated.

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%, so the description carries the load and does so for three of four parameters: name (partial match against name or alias), offset/limit (pagination, capped at 200), and world_id implicitly as the required scope. It omits defaults (limit=50, offset=0) and matching behavior like case sensitivity.

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 ('List a world's characters'), scopes what is included (player characters and NPCs), and even declares the return shape (one-line summary plus character_id). The plural 'List' cleanly separates it from the singular sibling get_character.

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 implied — you call it to enumerate a world's characters, optionally narrowed by name — but there is no explicit guidance on when to use this versus get_character (for full detail) or how it relates to get_character_images. No when-not-to-use statement is present.

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