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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds that output is source-backed and that block selection is constrained to 'compatible' blocks, which is useful context, but says nothing about return format, determinism, or failure modes.

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?

One sentence, no filler, front-loaded on the verb and the produced artifact. Efficient, though it is arguably too terse to be fully useful rather than merely concise.

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 and 0% parameter documentation, the description leaves an agent guessing about the input contract and the shape of the returned page plan. For a composition tool whose output drives downstream work, this is incomplete.

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 0%, so the description must carry the load and does not. It alludes to sections ('each requested section') but never explains what 'prompt' means, how sections relate to prompt, or the 8-item cap.

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 description states a specific verb and artifact: 'Create a source-backed page plan.' It adds the distinguishing mechanism ('selecting compatible Watermelon blocks for each requested section'), which separates it from the catalog browsing siblings. It never names a sibling explicitly, so it falls short of 5.

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?

There is no statement of when to choose this tool over catalog_summary, get_catalog_entry, or search, nor any prerequisite or exclusion. 'Per requested section' hints at input shape but not at usage context.

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