append

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

The description discloses detailed behavioral traits: insertion with exactly one blank line, heading creation behavior, failure on nonexistent topic, timestamp bumping, and retention never shortening. This goes well beyond the annotation (destructiveHint: true) and gives the agent a clear model of side effects.

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 compact and front-loaded with the primary purpose. Each subsequent sentence adds meaningful behavior detail without unnecessary fluff. It is well-structured and easy to parse.

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 moderate complexity, the description covers failure conditions, side effects (timestamp), and retention semantics. Since an output schema exists, return values are not needed in the description. It is sufficiently complete for effective invocation.

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 schema already provides descriptions for all parameters (100% coverage). The tool description adds extra meaning for 'heading' (appends under existing ## heading or creates it) and 'retention' (extends but never shortens). This enriches understanding beyond the schema, warranting a score above the baseline.

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 action: 'Append text to an existing topic.' The phrase 'without rewriting the whole body' differentiates it from sibling tools like write and edit, making the purpose specific and 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?

The description implies when to use this tool (when adding text to an existing topic without rewriting the whole body) and provides context about behavior (e.g., heading handling, failure if topic doesn't exist). However, it does not explicitly name alternatives or state when-not-to-use, so it falls short of a 5.

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