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 the shape of returned entries (the 'kind' discriminator and the id field), but no behavioral traits such as auth requirements, scoping to the calling user beyond 'the user's projects', or pagination/limits.

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 the purpose before the interpretive detail and the downstream id guidance. Every sentence earns its place, though the phrasing is slightly dense with the parenthetical about world tools.

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 and no parameters, the description must carry the return-value burden, and it does explain the two entry kinds and the id field the agent needs. It stops short of enumerating the remaining entry fields, leaving some gaps for a lookup tool whose output the agent must interpret.

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 tool takes zero parameters, so the baseline is 4; there are no arguments to mis-specify. The description still adds value by telling the agent what to do with the returned id, which is the only 'parameter-like' information relevant to this call chain.

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 the user's projects') and decodes the tool name by explaining that projects come in two kinds, 'world' and 'story'. However, it never differentiates itself from the sibling list_worlds and list_stories tools, so an agent cannot tell from the text alone whether this is the general listing or one of the specialized ones.

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 downstream routing: entries of kind 'world' should be handled with the world tools, and the returned id is to be reused as projectId in the world bible tools. This is clear contextual guidance, but it offers no exclusions or explicit comparison against the sibling listing tools (list_worlds/list_stories).

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