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

Annotations already declare this is a non-read-only, non-destructive, non-idempotent write. The description adds the 'private' visibility scope and clarifies the operation does not touch canon or scenes, which is useful mutation-boundary context. It says nothing about permissions, reversibility, or what the created project contains.

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 short sentences, front-loaded with the core action and followed by the scope exclusion. No padding, though 'when the user asks' is low-information filler that could be sharpened.

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?

An output schema exists so return values need not be explained, and the parameter set is small. However, with 0% schema coverage the description leaves both parameters semantically undefined, which is the main completeness gap for an otherwise simple create tool.

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 0% — neither 'name' nor 'description' has any documentation in the schema, and the description adds nothing about their meaning, length limits, or expected content. For a 2-param tool with zero coverage, the description should have compensated and does not.

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 ('Create a new private story project') and adds the distinguishing 'private' qualifier. The follow-up sentence ('Does not save canon or scenes') separates it from canon/scene siblings, though it never names an alternative tool directly.

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 trigger condition is only 'when the user asks,' which is vague and applies to nearly any tool. The exclusion ('Does not save canon or scenes') does hint at when to prefer siblings like upsert_canon_entry, but no explicit alternative is named.

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