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

Annotations already mark the tool as read-only, idempotent, and non-destructive. The description adds useful behavioral context beyond that: the default/max window, the inclusion of driving episodes, and the normal expectation of zero plays for newly indexed feeds. No contradiction with annotations.

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 only three sentences, front-loaded with the core behavior, then usage context, then a caveat. Each sentence earns its place. The first sentence is slightly ambiguous ('Plays over a window...') but overall it is concise and well-structured.

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 should convey return semantics, and it does: plays over a window plus episodes. It also provides default/max values and a real-world caveat. The main gap is a more explicit return shape or field list, but for a read-only stats tool the description is reasonably complete.

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 descriptions cover tenant_slug and token, while the days parameter lacks a description. The tool description helps by explaining the window default and maximum, which maps to days. This partially compensates for the missing schema description but does not add detail about token or slug.

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 conveys that the tool returns play counts over a configurable window (default 30 days, max 365) plus the episodes driving those plays. It lacks an explicit imperative verb like 'retrieves' or 'lists,' but the meaning is clear from the title and description, and it is distinct from sibling tools.

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 description explicitly states what questions the tool answers ('how did last month go' and 'which episode is working') and provides a practical caveat about zero plays on new feeds. It does not name alternative tools or exclusions, but the usage context is clear.

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