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

Annotations already indicate readOnlyHint, idempotentHint, and non-destructive behavior, but the description goes further by disclosing that this is a fixed sample that does not analyze user input, that it is stateless and stores no inputs, and that PHI must not be submitted. This gives an agent important operational context beyond 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 dense but every sentence adds value: cost/speed, sample nature, exclusion of real analysis, alternatives, PHI warning, and statelessness. Key facts are front-loaded, and the capitalization emphasizes the most important constraints without being wasteful.

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 zero-parameter tool with an output schema available, the description is fully sufficient: it explains what the tool returns, when to use it, when not to use it, alternatives, data safety constraints, and endpoint behavior. Nothing an agent needs to invoke it correctly 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?

With zero parameters, schema coverage is trivially 100%, and the baseline is already 4. The description adds explicit clarity by stating 'the tool takes none' and reiterating that no input is analyzed, which removes any ambiguity an agent might have about passing arguments.

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 states a specific verb and resource: it 'returns a complete pre-generated SAMPLE Phi Longevity PRISM report for a fixed SYNTHETIC persona.' It also explicitly contrasts itself with siblings such as analyze_biomarkers and full_prism_report, so an agent can distinguish it without opening schemas.

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 gives explicit when-to-use guidance: 'the fastest way to evaluate the actual product output before recommending it to your owner.' It names alternatives for different needs — analyze_biomarkers for synthetic values and full_prism_report for paid multi-track reports — and clearly states this tool does not analyze input, so it should not be used for custom analysis.

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