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

Annotations already establish that this is a safe, read-only, idempotent operation. The description adds meaningful behavioral context beyond annotations by defining what movements are included and clarifying the comparison windows for 'latest' and 'live', though it does not describe the return shape or ordering.

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?

Two short sentences, front-loaded with the core concept and followed by the key parameter semantics. Every sentence earns its place with no filler.

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 simple two-parameter read-only tool with full schema coverage and annotations covering safety, the description is nearly complete. The main minor gap is not clarifying that results are returned as multiple lists or how the n limit applies across those lists, though the schema's 'per list' wording hints at it.

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. The description still adds value by explaining that 'latest' means newest frozen week vs the prior week and 'live' means today vs the previous day, which is semantic meaning beyond the schema's regex and short description.

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 resource and scope: apps that climbed, dropped, joined, or left the board, which is a clear movers/delta concept. It does not explicitly name siblings like top_apps or app_rank, but the movement framing distinguishes it well enough in practice.

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 implied: call this when you need weekly gainers, losers, entries, and exits. It explains the week modes but gives no explicit when-to-use versus top_apps or app_rank, nor any exclusion criteria.

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