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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds value beyond that by enumerating the returned fields (storyId, world, persona, chapter count, word count, last update) and by hinting at the paging model via cursor, which no structured field provides.

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 tight sentences, front-loaded with the resource and scope, followed by return values and then filtering guidance. Every sentence carries distinct information with no filler.

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 does the work of describing return values, and it covers filtering and paging adequately against 100% schema coverage and full annotation coverage. Minor gap: no explicit statement of default/max limit behavior in prose, though the schema covers it.

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 coverage is 100%, so all four parameters are already documented in the schema. The description's filter hints for q and worldId largely restate the schema descriptions rather than adding syntax, format, or edge-case detail, 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 (List) and resource (stories), then disambiguates with synonyms (sessions, saves) and a definitional gloss ('private playthroughs they write inside a world'). This clearly separates it from siblings like list_worlds, list_scenarios, and search_stories.

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?

Gives concrete usage guidance ('Filter with q ... or worldId instead of paging through everything'), which tells the agent how to avoid inefficient pagination. It does not, however, explicitly contrast with the sibling search_stories or state when-not to use this tool.

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