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

Annotations already declare the read-only, idempotent, non-destructive behavior. The description adds valuable behavioral context beyond that: an active subscription is required, the output is 'not personalized advice,' and the portfolio is one specific rules-based construction. This gives an agent a clear expectation of access needs and limitations.

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 compact and front-loaded with the core definition, then adds the public counterpart, subscription requirement, and a key caveat. The first sentence is dense and somewhat long, but every clause conveys meaningful detail without redundancy.

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 read-only portfolio retrieval tool with a simple parameter schema and an output schema present, the description covers what matters: construction methodology, access requirement, relationship to public evidence, and the non-advice caveat. Nothing essential for calling this tool 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?

The schema already fully documents the only parameter (n) with an enum and description. The tool description does not add parameter-specific detail beyond the schema, so it does not exceed the baseline. It does provide portfolio context that helps interpret the result, but not the parameter itself.

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 precisely identifies what this tool returns: a specific rules-based model portfolio with construction details (momentum ranking, inverse-volatility weighting, volatility targeting) and the names the engine is standing aside on. It is clearly distinguishable from a generic 'get portfolio' and relates itself to the public walk-forward evidence.

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 strong contextual guidance: it requires an active subscription, is not personalized advice, and is the same construction as the public endpoint at /api/model-portfolio-evidence. It does not explicitly name sibling tools or state exact conditions for choosing this tool over alternatives, but the context is clear enough.

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