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

Annotations already declare readOnlyHint, non-destructive and closed-world, so safety is covered; the description's 'Read-only, no parameters' largely repeats that. It does add genuinely useful context the annotations cannot, namely the exact return payload (folders with projects/projects_with_subfolders counts and top_level_projects), which matters since there is no output schema.

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?

Front-loaded with what the tool returns, then a dense but purposeful when-to-use clause enumerating the affected siblings. The sibling list makes the second sentence long, but every clause earns its place; 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?

For a zero-parameter, no-output-schema listing tool, the description supplies purpose, trigger conditions, the exact return structure, and the intended downstream workflow. Nothing an agent needs to call it correctly 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 tool takes zero parameters, so the baseline is 4. The description correctly confirms 'no parameters' and the empty schema with additionalProperties:false leaves no ambiguity, though there is nothing further to explain.

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 ('Lists the folders of the user's Showoff projects') plus the concrete output shape (paths such as 'Showoff/Trailer'). This is easily distinguishable from siblings like list_projects or list_templates without opening any schema.

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?

Explicitly names the downstream tools that consume the folder value (list_projects, create_project, edit_scene, create_launch_video, update_launch_video) and states the condition to call it: reuse an existing folder rather than inventing a new one. Nothing is left to inference.

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