Add client note

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

Annotations declare a non-destructive, non-idempotent write; the description adds real context beyond that: the write is append-only ('keeping what is there'), the text is auto-prefixed with today's date, the note is business-private, and the client receives no notification. The notification-free and append semantics are exactly the side effects an agent cannot infer from the 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?

Three short sentences, front-loaded with the action and its preservation guarantee, followed by model context and the non-notification fact. No filler or restatement of the tool name.

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 two-parameter append mutation with annotations and no output schema, the description covers the essentials: what is added, what is kept, who can see it, and that the client isn't notified. It doesn't say what the call returns or what happens at the 1000-character limit, but neither is critical to correct 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?

Schema coverage is 100%, so both parameters are already documented in the schema, establishing the baseline of 3. The description adds only the implication that the caller supplies the line text while the date prefix is generated, which is marginal beyond what the schema states.

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 ('Add a dated line to a client's private note') plus the key invariant that existing text is preserved. The second sentence explains the underlying model (one private note per client card), which separates it from update_client and other client mutators.

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?

Gives clear context for when this tool applies: you want to append a timestamped observation to the single private note rather than overwrite client fields. It doesn't explicitly name an alternative (e.g. update_client) or state exclusions, so it stops short of full routing guidance.

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