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

Annotations already declare readOnlyHint=true and idempotentHint=true, covering the safety and side-effect profile. The description adds value by disclosing the content scope: data coverage, freshness, methodology, and limitations. This goes beyond the annotations without contradicting them, though it does not mention any potential delays or rate limits. With the annotation coverage, this is a solid 4.

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 concise sentences. The first sentence states the output scope, and the second provides usage context. Every word earns its place, with no redundancy or fluff. It is front-loaded with the key information.

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 no parameters, and an output schema is present (though not shown), so return format is covered. The description explains what the tool returns and when to use it, which is sufficient for an agent to decide when to call it. Given the simplicity of the tool and the annotation coverage, nothing is missing.

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 tool has zero parameters, so the description has no parameter burden. The baseline for 0 params is 4, and the description does not need to explain anything further. Schema coverage is 100% (empty properties), so nothing is missing.

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 starts with a specific verb 'Return' and names the exact resource: 'Scrykeeper's current data coverage, source-specific freshness, methodology and limitations.' This clearly distinguishes it from sibling tools like get_author, get_story, and search_market, which target individual entities or market searches. The purpose is unambiguous and highly specific.

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 this when interpreting reader, author or commercial metrics.' This provides clear contextual guidance. However, it does not mention when not to use it or name alternative tools, so it falls short of a 5 but is well above the minimum.

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