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

With annotations already declaring readOnlyHint=false and destructiveHint=true, the description adds the key non-obvious trait: projects cannot be deleted from here, so creation is effectively permanent. It also tells the agent what is returned (the project id) and how it is propagated to subsequent calls. It does not mention permissions or 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 action, then the return value, then the usage note, then the constraint. 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?

No output schema, but the description covers the return (project id) and irreversibility. The gap is the complete absence of parameter guidance for a tool with 0% schema description coverage, leaving emoji semantics entirely undefined.

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% and there are two parameters (required `name`, optional `emoji`), yet the description never mentions either. The agent must infer that name is the project name and emoji is a display icon purely from field names and minLength constraints.

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 ('Creates a project') and even defines the resource ('one more site or brand under the account'), plus the return value (its id). It doesn't explicitly differentiate from other create_* siblings, but the resource is unambiguous.

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 downstream usage guidance (pass the returned id as the `project` argument or via x-fnlowl-project / FNLOWL_PROJECT) which implies when this is needed, but never says when to create a project versus working within an existing one or calling list_projects first.

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