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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds real context beyond that — markdown output, a fixed time window (last week plus four weeks), missing-data carve-outs ('when one exists'), and a suggested file path — but says nothing about generation cost, latency, or what an empty product returns.

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 purpose and time window are front-loaded, and the long content enumeration is information the agent needs because there is no output schema. It is dense but not padded; a short lead-in verb would improve scanability.

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 carries the full burden of describing the return value and does so thoroughly: markdown format, every section (metrics, keep/stop lists, unattributed signups, narrative, pending approvals), and a filename convention. Nothing an agent needs to call or consume the result is missing.

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% for the single productId parameter, so the schema already does the documentation work. The description only reinforces scope with 'for one product', adding no id format or sourcing detail; baseline 3 is appropriate.

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 names the specific artifact (the 'what-worked report for one product as markdown') and enumerates its sections, so an agent can tell it apart from report_conversion or results by deliverable rather than guessing. The generating verb is implicit — it reads as a noun phrase ('The ... report') rather than 'Generates a weekly report' — but the scope and output form are unambiguous.

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?

Usage is only implied: 'last week and four weeks per channel' plus 'Ready to paste or save as reports/YYYY-MM-DD-growth.md' signals a weekly digest deliverable. It never states when to prefer this over report_conversion or results, nor any prerequisite such as the product needing tracked links or a completed sync.

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