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

With no annotations, the description carries the full burden and does substantial work: it discloses that rating movement is measured from the first scored snapshot on or after `since`, that every row includes `was` and `compared_to`, and that `basis` indicates recorded history vs. last-build trend fallback. This is rich behavioral context beyond the bare operation.

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 description is dense but every clause earns its place; it front-loads the core 'what changed' message and then clarifies key behavioral details. The single long sentence is slightly harder to parse than structured bullets, but it remains efficient and free of 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?

Given no output schema and no annotations, the description does well by explaining the output fields (`was`, `compared_to`, `basis`) and the fallback behavior. Minor gaps remain around result ordering, pagination, and whether added vs. updated providers are separated, but these are not critical for correct invocation.

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 67%, covering `since` and `context` while leaving `limit` described only by schema constraints. The description adds important semantic nuance to `since` by defining how the comparison baseline is chosen, which is meaningfully more than the schema's 'YYYY-MM-DD'.

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 purpose: what changed in the catalog since a date, including providers added/updated and rating movement. It is detailed enough to distinguish the tool from the many find_* and get_rating_history siblings, even without naming one.

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 context is implied through the 'since a date' framing and the explanation of how rating movement is measured, but there is no explicit statement of when to choose this tool over alternatives like find_rating_movers or get_rating_history. No exclusions or alternative routing are provided.

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