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

Annotations already establish read-only, idempotent, open-world, non-destructive behavior. The description adds useful behavioral context beyond that: it reports session coverage, aggregate counts, and which additive records could not be retrieved. There is no contradiction with the annotations.

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 compact sentences with no filler. The first sentence front-loads the verb and the resource, then lists report contents; the second gives a crisp use cue. Every sentence adds value.

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?

For a no-parameter reporting tool with rich annotations, the description is complete enough. It names the exact contents of the report—sessions, counts, unretrieved records—which substitutes for the missing output schema, and it gives a clear operational use case.

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 and the schema coverage is effectively 100%, so the description cannot add parameter-level meaning. Per the baseline rule for zero-parameter tools, a 4 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 uses a specific verb ('Report') with a clear resource ('what this Codex GSFA dataset contains') and enumerates concrete report contents: sessions represented, counts of additives, food categories, provisions, and unretrieved additive records. This distinguishes it from sibling search and query tools such as gsfa_search_additive and gsfa_food_category_additives.

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 to check the freshness and completeness of GSFA answers before relying on them.' It gives clear context, but it does not state when not to use it or name alternative tools, so it stops short of a 5.

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