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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and closed-world, so safety is covered. The description adds that the output is cast into named bands ('idle tab to daily utility'), which is genuinely useful since there is no output schema. It does not, however, describe band count, thresholds, or precision.

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?

Front-loaded with the core purpose in one efficient sentence. The trailing marketing URL is arguably non-essential, but the whole description is short and wastes little space.

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 pure calculator with no output schema and full annotation coverage, the definition supplies enough to invoke it correctly. The banding phrase gives a rough sense of the result; only explicit threshold/band details are absent, which is acceptable given no output schema.

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% with two clearly labeled numeric parameters (dau, mau), so the schema carries the parameter burden. The description mentions the DAU/MAU ratio concept but adds no format, range, or unit detail beyond the schema. Baseline 3 applies.

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 ('Grade product stickiness') plus the exact inputs (DAU/MAU) and the output shape (bands from idle tab to daily utility). This distinguishes it from sibling graders like product_market_fit_scoring_grader or product_tour_effectiveness_grader, though it does not name those siblings explicitly.

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?

No guidance on when to use this tool versus alternatives, no prerequisites, and no indication of when it is inappropriate. The only extra sentence points to an external website, which is not usage guidance.

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