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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds genuine behavioral context beyond that: normal results return names and cheapest listing prices, while a slug query switches to a rich single-item payload with per-marketplace prices — useful mode-switching disclosure.

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 tight sentences with zero filler: the first establishes scope and exclusions, the second establishes the two return modes. Nothing is buried or redundant.

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 burden of describing returns and does so for both modes (list vs. single-item detail). Minor gaps remain around pagination/filter interaction with the slug mode, but an agent has enough to call it 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 coverage is 100% with 6 well-documented parameters, so the baseline is 3. The description's only parameter-adjacent content — that a slug returns one item with full detail — restates what the schema's own slug description already says, so it adds no new semantic value.

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?

States a specific verb (Search) plus the exact resource (Counter-Strike 2 cosmetic items) and immediately scopes it by exclusion — 'not weapon skins' — enumerating the six covered categories. This lets an agent separate it from search_skins without opening either schema.

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 'not weapon skins' exclusion plus the category enumeration gives clear routing guidance against the sibling search_skins and browse_* tools, and it notes the slug-driven single-item mode. It stops short of naming the alternative tool explicitly or stating when-not-to-use conditions.

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