Download trend

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

Annotations already declare readOnly/idempotent/non-destructive/open-world, so the safety profile is covered. The description adds genuinely non-obvious behavioral detail: how growth is computed (halves of the window, not endpoint-to-endpoint) and why (weekly seasonality), which materially affects how an agent should interpret the output.

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 front-loaded sentences: the first states the output, the second justifies the growth methodology. Every clause earns its place, though the seasonality rationale is somewhat verbose relative to the tool-selection job the description is doing.

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?

With no output schema, the description carries the return-value burden and does so: downloads, unique listeners, growth rate, and peak period. Combined with 100%-covered params and full annotations, an agent has everything needed to call and interpret this tool without opening anything else.

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%, including the accepted identifier formats, relative date syntax, bots default, and granularity guidance, so the baseline is 3. The description's 'bucketed by day, week or month' restates the enum without adding syntax, format, or constraint detail beyond the schema.

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 names the exact resource and shape of the analysis: a show's downloads and unique listeners over a window, bucketed by day/week/month, plus growth rate and peak period. That specificity implicitly separates it from aggregate siblings like op3_show_downloads or op3_episode_downloads, but no sibling is named, so an agent still has to infer the boundary.

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?

There is no explicit when-to-use, when-not-to-use, or alternative tool callout, despite several overlapping siblings (op3_show_downloads, op3_query_downloads, op3_episode_downloads). The only usage hint — 'use week or month for windows longer than a couple of months' — lives in the schema for granularity, not in the description.

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