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

With no annotations, the description bears full burden. It discloses that the tool returns names and cheapest listing prices for multi-result searches, or full per-marketplace prices for single-item lookup. No destructive behavior is implied. It omits mention of rate limits or auth, but those are not expected for a read-only search 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?

Two sentences, zero waste. First sentence states purpose and scope, second states return format. All key information is front-loaded.

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?

Given 6 parameters, no output schema, and no annotations, the description covers the tool's purpose and behavior adequately. It explains both list and detail modes. Lacks explicit discussion of pagination behavior, but schema covers page/per_page limits.

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%, baseline 3. Description adds nuance: explains that 'slug' triggers single-item detail with per-marketplace prices, and 'search' is free-text. It does not explain sort enum values beyond schema, but overall adds meaningful context.

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?

Description uses specific verb 'Search' and clearly delimits resource: CS2 cosmetic items excluding weapon skins. It lists exact categories (stickers, charms, etc.) and states two possible return formats (list with cheapest prices, or single item with full detail). This differentiates it clearly from sibling tools like search_skins.

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 implies usage context: for non-weapon cosmetics. It explains that setting slug returns full detail, which guides the agent on when to use that parameter. However, it does not explicitly state when not to use this tool (e.g., if you need weapon skins, use search_skins).

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