list_libraries

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

No annotations and no output schema exist, so the description carries the full disclosure burden — and it does the important part by enumerating the returned fields (name, version, compatible renderers, license, description). It doesn't mention pagination, ordering, or whether the catalog is static or network-fetched, which are the remaining unknowns for a zero-parameter read.

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: purpose first, return shape second, downstream usage third. Nothing is repeated from the schema or title, and every sentence adds information an agent needs.

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 zero parameters, no annotations, and no output schema, the description supplies exactly what's missing: what the entries contain and how to consume them. It is nearly complete, though a note on catalog size or freshness would help an agent decide whether to call it eagerly.

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 there is nothing for the description to disambiguate; baseline 4 applies. The only parameter-like reference is the `libraries` array on create_sketch, which is correctly attributed to the sibling rather than to this tool.

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 all curated external library presets') and immediately ties the resource to its consumer, create_sketch. An agent can distinguish this discovery tool from sibling mutation tools like create_sketch or list_sketches 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?

The description gives a clear call-to-action for what to do with the output: 'Pass a library name in the `libraries` array of create_sketch to include it.' That makes the workflow position (pre-step to create_sketch) explicit. It stops short of stating any exclusions or alternatives, but with a single obvious purpose that omission is minor.

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