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

Annotations already declare readOnlyHint=false, idempotentHint=true and destructiveHint=false, so safety is covered. The description adds real behavioral context beyond them by explaining what locking protects against ('replanning never changes it'). It does not cover error behavior for dates with no planned dinner or whether unlocking preserves the existing meal.

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?

A single sentence with the primary action and the motivating effect front-loaded, plus the boolean semantics attached inline. Nothing is redundant and nothing needs to be moved earlier.

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, fully documented, non-destructive idempotent toggle with no output schema, this is nearly complete. Only edge-case behavior (locking a date with no dinner, error responses) is missing, which is a minor gap.

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 the baseline is 3, and the description goes slightly beyond by explaining the effect of pinned=true (replanning will not alter it) rather than merely restating the boolean mapping. The date parameter's meaning is left entirely to the schema, which is adequate here.

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 ('Lock a day's dinner ... or unlock it') and immediately qualifies the semantics with the parenthetical locked=true mapping. It is clearly distinguishable from siblings like replace_dinner or replan_open_days because it operates on lock state rather than the meal itself.

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 a clear motivation for use: lock when you want replanning to never change the dinner, unlock to release it. It does not explicitly name the alternative tools (replace_dinner, replan_open_days) or state exclusions such as whether the date must already have a planned dinner, so the routing guidance is strong but not complete.

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