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

With no annotations, the description carries the transparency burden, and it discloses non-obvious behavior: the current day is excluded from averaging and returned separately, and feeds that turned on inside the window are explicitly flagged. It doesn't describe the response shape or mention read-only/auth behavior, so it isn't 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, front-loaded with the core output then the edge-case behavior. The explanatory clauses ('so a window can be read...', 'because a rise...') are helpful but slightly ornamental, so it earns a 4 rather than a 5.

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?

It covers purpose, usage, and algorithmic edge cases, and the schema covers parameter syntax thoroughly. The main gap is the absence of an output schema combined with no explicit statement of the response structure, which leaves some ambiguity for an agent calling without prior knowledge.

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%, with detailed descriptions for each of the 7 parameters, so the description doesn't need to clarify them. The description's only parameter-related contribution is calling everything a 'filter'; it adds no meaning beyond the schema, which lands exactly at baseline.

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 clearly identifies a data-analysis activity: per-day record counts for a filter plus a median baseline, and it distinguishes this from plain record listing by emphasizing comparison to a window's own normal. It doesn't explicitly say 'returns' and relies on the schema for filter mechanics, so it stops short of a 5.

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?

It gives a clear intended context: read a time window against its own normal and avoid misreading new feeds as real growth. It does not name sibling alternatives or provide explicit when-not-to-use exclusions, which would be needed for a 5.

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