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

Annotations already declare destructiveHint=true and idempotentHint=true, so the safety profile is covered; the description adds real context by defining the coordinate frame ('measured from the bed's top-left corner') and the footprint semantics. It does not say what happens to a planting's prior position when it is moved or whether overlaps with neighbors are allowed, which keeps it out of the top band.

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 sentences, front-loaded with the action and its effect, then parameters, then usage and the exclusion. No filler and nothing buried at the end that an agent needs first.

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 7-parameter mutation tool with no output schema, the description covers purpose, units, coordinate origin, identifier options, usage context, and a fallback path. It omits any mention of the 'garden' parameter (the schema covers its default), which is a minor gap rather than a blocking one.

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%, so the baseline is 3; the description earns an extra point by stating the either/or relationship between plant name and plantingId, which the schema presents as two independent optional properties with no indication they are alternatives. The coordinate-origin explanation is helpful but partly duplicates the schema's 'X offset from the bed's top-left'.

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 pair ('place or move') and resource ('a planting on its bed's layout grid'), plus the exact effect (sets position and footprint in cm). This is clearly distinguishable from siblings like add_planting, update_planting, and get_bed_layout without opening any schema.

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?

Explicitly says when to use it ('when the user wants to arrange, position, or move a plant within its bed') and gives a when-not with an alternative ('a planting that already spans several grid squares, use the app's layout editor instead'). It stops short of routing between this and the sibling tools add_planting/update_planting, which is the remaining gap.

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