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

Annotations already communicate readOnly, idempotent, open-world, and non-destructive behavior. The description adds meaningful context beyond those hints: the 'you own' scoping and the ref_role semantics on the first panel, last distinct panel, and otherwise null. This is genuine behavioral detail that helps the agent interpret rows correctly.

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?

The description is compact and well organized: an initial statement of what the tool returns, a practical usage instruction, and then the most important data nuance about ref_role. No filler or repeated annotation information is included.

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, single-parameter listing tool that already has an output schema and read-only/idempotent annotations, this description is complete. It tells the agent what it will get and why, and the workflow guidance removes the likely source of misuse. Nothing critical is missing.

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?

The input schema already fully documents the only parameter, story_id, with an explanation and example. The description does not add new parameter-level semantics beyond saying the panels belong to a story, so a baseline score of 3 is appropriate because the schema carries the load.

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 uses specific verbs and resources: it 'List[s] panels you own for a story', identifies the primary value returned (panel_id), and mentions the story context. It also distinguishes this tool from the sibling mutation tools by framing it as the lookup step before continue_story or regenerate_panel.

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 gives an explicit usage rule: use this tool to get panel_id values 'before changing Image 1 or Image 2 on manga.continue_story or manga.regenerate_panel.' This tells the agent both the task and the correct sequencing relative to two sibling tools, so there is no ambiguity about when it should be called.

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