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

The annotations indicate a safe, read-only, idempotent query. The description also states two behavioral results that are not in the schema: it compares the estimate against the shop's own post reach and links to the Boost page in Xyla. It doesn't say anything about estimation accuracy, rounding, or a time horizon beyond "each month", which keeps it just below a 5.

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 with no filler. The estimate, the use case, and the comparison behavior are front-loaded and each carries independent information.

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?

This is a simple read-only, single-optional-parameter tool with no output schema, and the description says enough for an agent to call it and interpret the result. The only gap is uncertainty about the response shape (a number, a range, or a comparison), which the description only hints at.

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% and the single parameter is fully documented, including its default of 10 and the 5–50 bounds. The description restates the $5–$50 range but adds nothing new, such as what happens when the parameter is omitted. Baseline 3 is correct when the schema already does the heavy lifting.

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 uses a specific verb ("Estimates") plus a clearly bounded resource and output ("how many more people and store visits this Xyla shop could get each month with Boost") and names the budget range. That's specific enough that an agent can distinguish it from sibling tools like insights or shop_overview without needing to open 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?

The description gives concrete usage triggers ("Use it when the merchant asks how to get more reach, followers, traffic or sales"), which is strong positive routing. It doesn't explicitly exclude alternatives (e.g., insights for organic performance, or when the merchant wants an exact conversion forecast), so the when-not side is left implicit.

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