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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so the agent knows this is a safe, repeatable read operation. Description adds the term 'bounded' which hints at scope but doesn't explain what 'bounded' means (e.g., workspace-scoped, project-scoped) nor mention pagination behavior that offset/limit implies. No contradiction with annotations.

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?

Single sentence, 14 words, zero waste. Each part ('List', 'bounded reusable characters', metadata details) serves a clear purpose. Front-loaded with the action and resource.

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?

Despite low parameter description coverage, the output schema exists and parameter names are clear. The description lacks a note about workspace scoping or archived behavior, but for a simple list tool with rich annotations and output schema, it is largely complete. Could mention that workspaceId is optional and defaults to user's default.

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 covers 4 parameters but description coverage is only 25%—it does not mention or elaborate on any parameter. However, the output schema exists and parameters like limit/offset/workspaceId/includeArchived are self-explanatory from names and schema defaults. Baseline 3 is appropriate since description adds no value beyond schema, but schema names provide adequate context.

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?

Description states specific verb ('List'), resource ('bounded reusable characters'), and included data ('identity, voice, facts, and image-reference metadata'). It clearly distinguishes this tool from sibling tools like characters_get or characters_apply by framing it as a list operation. However, it doesn't explicitly differentiate from other list tools in the sibling set.

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?

Implied usage is listing characters, but no explicit guidance on when to use this vs alternatives like characters_get (for a single character) or characters_apply (for applying characters). No exclusion criteria or context about filtering, pagination, or prerequisites beyond schema-bound parameters.

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