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

With annotations already declaring readOnlyHint=false, openWorldHint=true and destructiveHint=false, the description still adds meaningful non-structural context: no confirmation step is required, the value becomes visible to the client, and a scoped Cotlet API key is needed. These are exactly the kind of write-side traits annotations cannot express.

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?

Four short sentences, purpose front-loaded, each carrying a distinct fact (action, channel, precondition, auth). Minor verbosity in "as a coach would... on the client calendar" and the "does not ask for your OK" phrasing, but nothing is wasted.

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 mutation tool with existing annotations and no output schema, the definition covers purpose, precondition, visibility side effect, and auth requirement. The main omission is any note on failure behavior when the metric is not assigned.

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 each parameter (date, value, metric, client_id) documented including cross-references to list_metrics and list_clients. The description adds no format or unit detail beyond the schema, so the baseline 3 applies.

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?

"Record a new value for one of a client's metrics" gives a specific verb and resource, and the follow-up sentence clarifies it as the equivalent of a coach action in the Metric Manager. It is clearly distinct from the read-side sibling truecoach_list_metrics, though it does not name that sibling in the text.

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?

States a real precondition: "The metric must already be assigned to the client," which tells the agent this cannot be used to create new metrics. It gives no explicit when-to-use-vs-alternative routing, so it stops short of the top band.

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