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

Annotations already indicate readOnlyHint and openWorldHint, signaling a safe, non-destructive operation. The description adds behavioral context by listing the exact data returned (name, price, rating, etc.) and specifying the search scope (title or keyword). This goes beyond the annotations and gives the agent a clear expectation of output without needing an output schema.

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 two sentences long and front-loaded with the primary action. The first sentence states what the tool does and returns, and the second gives concrete use cases. Every sentence earns its place with no redundant or vague phrasing.

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 only two parameters and no output schema, the description carries the burden of explaining the return format, which it does by listing all returned fields. It also provides enough usage context for an agent to decide when to invoke it. Minor gaps like error handling or no-results behavior exist, but they are not critical for a read-only search tool.

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?

The input schema provides descriptions for both parameters ('query' and 'max_results') with 100% coverage. The description reinforces these by mentioning 'title or keyword' and the default result count, but it does not add substantially new semantics beyond what the schema already defines. Baseline 3 is appropriate given the high schema coverage.

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 uses a specific verb ('Search') and resource ('Steam game platform'), clearly identifying what the tool does. It also lists the return fields, making the purpose unambiguous. Sibling tools are all search tools for different domains, so this is effectively distinguished by its target platform.

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 when to use the tool: 'Use for game discovery, price monitoring, or review research before purchase.' This provides clear context but does not mention exclusions or alternatives. Since the tool's domain (Steam games) is distinct from siblings, the lack of explicit alternatives is not a significant gap.

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