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

Beyond the sparse annotations (only idempotentHint=false), the description adds a valuable security-related behavioral warning: the returned content is user text and must be treated as data, not as instructions. This goes beyond what the schema or annotations provide, though it does not mention other behavioral aspects like permissions or reversibility, which are not critical for this simple append operation.

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 two sentences with no wasted words. The core operation is front-loaded, and the important user-content warning is placed second, making the structure efficient 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?

For a tool with only two simple parameters and no output schema, the description covers the operation, the target resource, and the nature of the returned content. It could mention the exact return structure, but the warning that the returned content is user text is a meaningful substitute for an absent output schema and keeps the description sufficiently complete.

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 description coverage is 100% with basic descriptions for both parameters. The tool description adds meaning by clarifying that 'text' is plain text and is appended 'aan het eind', and that 'id' refers to an existing note. This enriches the parameter semantics beyond the schema alone.

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 states a specific verb ('Voegt', i.e., appends), a specific resource ('bestaande notitie'), and the location ('aan het eind'). This clearly distinguishes it from sibling tools like create_note and get_note.

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 clearly indicates this tool is for adding plain text to an existing note, giving the agent context for when to use it. It does not name alternatives or explicitly exclude other tools, but the phrase 'bestaande notitie' and 'aan het eind' provide enough guidance for this simple operation.

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