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

Goes well beyond the annotations: it discloses exactly what is destroyed (anything in the owner's file that is not in the standard, from the live file), what recovery exists (the dated copy kept beside), and what each no-write mode does to state. This matches destructiveHint=true and adds the precise scope of the loss.

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 opening sentence front-loads purpose well, but the all-caps mode blocks are shouty and partly restate the schema's own parameter descriptions. Content earns its place, but the formatting and repetition cost readability.

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?

With no output schema, the description steps in to say what preview returns — contents of the new version, where the file stands, what yes/no do, what would be lost, and the whole new text — so an agent knows what to expect. The write-mode response is only summarized, which keeps it from a 5.

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, but the description adds real semantics the schema cannot: the interaction between preview and decline, and the fact that decline takes effect without a rewrite. It does not add path formatting detail beyond the schema, so not a 5.

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 — rewrite this home's HOME.md in its Living Projects folder from the standard text — plus the side effect of keeping a dated copy. It is clearly distinguishable from read_home (reads) and setup_home (initial creation) 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?

Gives explicit mode conditions: preview=true answers and writes nothing, decline=true records the no and changes nothing else, and the write fires only on the owner's yes. It does not name sibling alternatives, so it falls just short of a 5, but the when/when-not guidance is unusually precise.

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