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

Annotations already declare readOnly, idempotent, non-destructive and openWorld, so the safety profile is covered. The description adds genuine behavioral context the annotations cannot convey: 'popular' is order-only with no sales numbers and is re-baked daily, 'just_released' applies a review floor, and 'steam_chart' reflects the previous month's gold/silver/bronze tiers.

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?

One front-loaded sentence plus an inventory sentence; the block definitions come first and the item-shape note comes last. It is dense with parentheticals but nearly every clause carries distinguishing information, so little is wasted.

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?

An output schema exists, so return values need not be detailed, and the description still sketches item contents (link, review score, tags). With a single optional enum parameter and full schema coverage, an agent has everything needed to call it correctly; only cross-tool routing is unstated.

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% and the enum values are already listed, so the baseline is 3. The description goes further by defining what each enum value actually contains (this week and last with a review floor, Early Access graduates, cozy releases, prior-month chart tiers), which is real semantic value 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 concrete resource (this month's Steam releases as shown on steamcozy.com/new) and enumerates the five block categories with their exact semantics, so an agent knows precisely what it fetches. It does not explicitly contrast itself with the siblings fetch/find_games/search, which keeps it just 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?

Usage is implied through the block catalogue and the note that omitting 'block' returns a digest of all blocks (10 items each), which tells the agent how to choose between full-block and overview modes. There is no explicit when-to-use/when-not guidance or reference to the sibling tools.

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