List characters

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds useful behavioral context: the exact fields returned and the special fallback behavior when no actor has the given type. This goes beyond the annotations without contradicting them.

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. The first sentence states the action, resource, output fields, and optional filter. The second sentence covers the edge case. Every word earns its place.

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 simple read-only list tool with one optional parameter and no output schema, the description is nearly complete. It covers the return fields and the no-match edge case. It doesn't describe pagination or sorting, but for a list of actors this is a minor gap, not a blocker.

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%, so the schema already documents the 'type' parameter. The description adds that the comparison is exact and gives an example ('npc'), which is helpful, but it doesn't go far beyond the schema. Baseline 3 is appropriate.

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 clearly states the tool lists actors/characters with specific fields (id, name, type, folder, image presence) and an optional type filter. It distinguishes itself from siblings like list-combats, list-users, and list-scenes by naming the resource (actors of the world) and the exact output fields.

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 description explains the optional type filter and even specifies behavior when no actor matches (names the existing types). It doesn't explicitly say when to use this over alternatives, but the resource and filter are clear enough that an agent can infer when to call it. A small gap: no mention of when to use get-character or search-character-items instead.

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