Save a user capability

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

Annotations already indicate destructiveHint and idempotentHint, but the description adds valuable details: it validates POML before saving, supports context parameterization, and restricts writes to the user-capabilities directory. It also clarifies that builtin capabilities cannot be modified, which is a behavioral constraint not obvious from the 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?

The description is concise and well-structured. It front-loads the purpose, then details content formats, and ends with a scoping constraint. Every sentence adds value without redundancy, making it easy to parse quickly.

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?

The description provides sufficient information for an agent to call the tool correctly: it explains the purpose, content format, and directory scope. Since an output schema exists, the return format does not need to be described. The only minor gap is the semantics of the overwrite parameter, which is not mentioned but is a boolean with a default in the schema, so it is discoverable.

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?

With 0% schema description coverage, the description must explain parameters. It does explain 'content' by specifying allowed formats (POML with validation and context parameterization, or plain markdown). It implicitly refers to 'name' as 'named capability', but it does not explain the 'overwrite' parameter at all, leaving its behavior unspecified. The description adds some meaning but does not fully compensate for the lack of schema documentation.

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?

The description clearly states the verb 'Save' and the resource 'a reusable workflow as a named capability'. It also differentiates from siblings by specifying the destination directory and that builtin capabilities cannot be modified, making it distinct from tools like delete_capability or save_pipeline.

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 explains when to use the tool: to save a reusable workflow as a capability for future sessions. It also gives context on content formats (POML or markdown) and a constraint (builtin cannot be modified), which implicitly guides when not to use it. However, it does not explicitly name alternative tools or provide direct comparisons with siblings.

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