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

Annotations say readOnlyHint=false and destructiveHint=false, and the description usefully discloses the actual mechanism: Toffu sends a confirmation link and nothing else goes out until the user clicks it, which is real behavioral context beyond the annotations. The remaining gap is that it never clarifies whether this persists as a stored setting (as the name set_report_email implies) or is a one-off send, and what happens on repeated calls.

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 ordered by importance: what it does, what happens next, how to source the parameter. No filler and no repetition of schema fields.

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?

An output schema exists so return values need no explanation, and the description covers the action, the confirmation gate, and the parameter-sourcing rule. The only missing piece for a mutation tool is the persistence/overwrite question the name implies.

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% for the single email parameter, so the schema already carries the baseline. The description still adds value by instructing the agent to elicit the address from the user and not fabricate it, which is behavioral meaning the schema does not convey.

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?

Names a concrete verb (send) and resource (the workspace's weekly campaign report) and a concrete destination (the user's email), so the agent knows exactly what the call accomplishes. It does not contrast itself with near neighbors like send_message, so it falls short of a 5 on differentiation, but the scope is 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?

Gives an explicit operating rule for obtaining the one input: ask the user for the address and never guess it. It stops short of naming when to prefer this over alternatives, but the narrowness of the purpose makes the trigger context clear.

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