update_library_message

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

Annotations already indicate idempotent and non-destructive. Description adds key behavior: existing content is fetched and preserved unless explicitly replaced, which implies merge/replace semantics and safety. Does not cover error conditions but adds value beyond annotations.

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 sentences, front-loaded with verb and resource, then behavioral nuance. No wasted words; every sentence serves a purpose.

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?

Given the tool's complexity and presence of annotations, the description covers the main behavioral nuance (merge/replace) and safety. It does not explain return values or require existence, but that is acceptable for an update tool without output schema.

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 coverage is 100% with parameter descriptions. The description clarifies that the 'messages' parameter merges with existing content and 'description' parameter replaces, adding semantic value beyond schema.

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 tool name 'update_library_message' and description 'Safely update a library message' clearly specify the verb (update) and resource (library message). It distinguishes from siblings like create, get, delete, and list by implying partial update with merge behavior.

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?

Description implies use when you want to update a library message while preserving existing content unless explicitly replaced. Does not explicitly state when not to use or compare to alternatives, but sibling tools are distinct.

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