discover_performance

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

No annotations are provided, so the description carries the full burden. It discloses the basic purpose but does not mention whether the tool is read-only, any permission requirements, rate limits, or pagination behavior. The 'limit' parameter suggests paginated results but is not explained.

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 a single sentence that is efficient and front-loaded, providing the essential purpose without any unnecessary words.

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?

The tool has an output schema (not shown) so return values are covered. However, with three parameters and no annotations, the description should at least explain the parameters. Given the simplicity and presence of output schema, the description is minimally complete but leaves gaps in parameter understanding for an agent.

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 description adds no information about the three parameters (days, site, limit). The schema has 0% description coverage, and the parameter names are only titled; the description does not explain their meaning, default values, or allowed formats. For an AI agent, this lack of guidance could lead to incorrect usage.

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 clearly states the tool retrieves Discover performance data (top pages by impressions) and explicitly notes that Discover does not support the query dimension, distinguishing it from search analytics tools. This gives a specific verb+resource and differentiates from siblings.

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 the use case is for Discover performance reporting. The note about the query dimension indirectly suggests not to use this tool for query-based analysis, which would be handled by tools like get_search_analytics. However, it does not explicitly state when to use this tool over others or provide alternatives.

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