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

Annotations declare destructiveHint=true and idempotentHint=true; the description adds the crucial scope of destruction ('from the current week on', 'past weeks stay unchanged'), which is not in the annotations. It does not disclose auth/permission requirements, but the destructive boundary is well communicated.

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 action and scope are front-loaded, and every clause carries information (dates, limits, ranges). It is dense and slightly run-on but free of filler.

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 destructive, no-output-schema mutation tool, the description supplies the replacement scope, constraints, and return reference ('as plan() does'). This is close to sufficient; only auth/permission context is missing.

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 0% and the nested object is opaque, so the description carries the full burden and largely delivers: it names the 'weeks' array and its fields (start, focus, targets), the date format, and numeric ranges for each target. It does not explain optionality or unknown-field handling.

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 verb 'Replace' and resource 'plan' are specific, and 'from the current week on' scopes it precisely. It implicitly distinguishes itself from the sibling plan() by wording the return as 'as plan() does', but does not explicitly frame plan() as the read counterpart.

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?

'Replace the plan from the current week on' plus 'Past weeks stay unchanged' tells the agent the exact effect and boundary. It stops short of an explicit when-to-use vs. plan() routing statement, but the context is clear.

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