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

Beyond the readOnlyHint annotation, the description discloses the data provenance (own snapshot series), the granularity (hourly), and the meaning of an empty response — real behavioral context an agent could not infer. It stops short of saying how much history is retained at the maximum window.

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 definition and the key edge case. The "Our unique moat — this data exists on no other service" sentence is promotional rather than operational, though it does hint at data uniqueness.

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?

An output schema exists, so return shape need not be explained, and a read-only tool needs little safety disclosure. Remaining gap is modest: the `days` bounds and board enum semantics are left entirely to the schema, which does not describe them.

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 only 33%: only `full` is documented as owner/name. The description compensates partially by tying "window" to the `days` parameter and confirming the board default, but it adds nothing about the 1–30 day bounds or what the board enum values signify.

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: a time series of one repository on one board, returning hourly rank plus star points. It is clearly distinguishable from get_repo (current snapshot) and get_board, though it never names those siblings explicitly to reinforce the split.

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 "empty result means the repo was not tracked in the window" note gives useful framing for interpreting output, and the default board is stated. But there is no explicit guidance on when to reach for this versus get_repo or the board-level movers tools.

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