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

No annotations exist, so the description carries the full behavioral burden. It discloses what the output measures (copies listed, share claimed at each age) which is genuinely useful, but says nothing about return format, pagination, or access constraints. Adequate but incomplete for a no-annotation tool.

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 cohort definition, then usage guidance, then the parameter hint. No filler, though the opening sentence is dense and could be split.

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 moderately complex aggregation tool with no output schema and no annotations, the description conveys the grouping unit, the metrics, and the 'at each age' framing an agent needs to interpret results. It leaves output shape and limits unspecified but is sufficient to invoke correctly.

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 100%, so grain, months, and creator_id are already documented. The description's 'Pass creator_id for one creator's releases' merely restates the schema's 'Omit for the whole market' scoping note. Baseline 3 when the schema does the heavy lifting.

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 defines the resource precisely: cohorts of finite UGC Limited releases grouped by week or month, with copies on sale and claimed share. It is a specific aggregation/reporting tool rather than a generic list. It does not explicitly name or contrast a sibling, so it falls 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 clear when-to-use context ('compare how fast recent drops sell through against earlier ones') and a methodological caveat ('compare cohorts at the same age_days'). It does not name alternative tools or state when not to use it, so no explicit routing.

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