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

With no annotations provided, the description carries the full burden for behavior disclosure. 'Get statistics' implies a read-only operation, and the description explicitly lists outputs and supported periods. While it does not mention rate limits or authentication, for a presumably stateless read endpoint, this is sufficient and clearly non-destructive.

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: the first states the core purpose and outputs, the second covers the period parameter. It is front-loaded with the key facts and has zero wasted 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?

Given the tool's simplicity (two params, no output schema), the description covers the essential use case: what it returns and the supported time periods. It stops short of describing return format or units, but with no output schema and the explicit list of metrics, it is adequately complete.

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% because both targetId and period have descriptions. The description adds no new parameter meaning beyond what the schema already specifies; mentioning 'lifetime, monthly, or weekly periods' merely restates the schema's period examples. Baseline 3 is appropriate.

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 verb 'Get' and the resource 'statistics for a specific target', listing the types of statistics returned (runs, pass rate, findings, duration). This distinguishes it from sibling tools like team_stats or get_target_scores by scoping to a specific target, making the purpose unambiguous.

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 when you need aggregate statistics for one target, and it mentions the supported periods (lifetime, monthly, weekly). However, it does not explicitly differentiate from alternative tools like daily_trends or list_runs, nor does it state exclusions such as 'for team-wide stats, use team_stats'.

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