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

Annotations already cover the safety profile (readOnly, non-destructive, idempotent, closed-world), so the bar is lower. The description adds genuine output behavior beyond that: no overall score is returned and an axis lacking sufficient history (e.g. no crisis in window) yields no reading rather than a guess.

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?

Purpose and the three axes are front-loaded, followed by usage routing and behavioral caveats. The phrasing is somewhat ornate ('what its risk is built from', 'for the risk taken'), but every clause carries information and nothing is redundant.

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?

With an output schema present the return values needn't be spelled out, yet the description still flags the two surprising output behaviors (no overall score, missing readings on short-history axes). Combined with the named alternative and full schema coverage, an agent has everything needed to call it correctly.

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 description coverage is 100%, so both parameters (holdings, base) are fully documented in the schema, including the weights-vs-amounts distinction and the USD default. The description lightly restates these, adding no meaning beyond the structured fields; baseline 3 applies.

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?

Names a specific verb+resource (a portfolio read) and enumerates the three axes it returns: concentration, resilience, efficiency. It also distinguishes itself from measure_portfolio, so an agent can route correctly without opening either schema.

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?

Gives an explicit trigger ('when the reader asks whether something is off in how the portfolio is built') and names the alternative for the broader case ('for the full measurement use measure_portfolio'). Both the when-to-use and the when-not-to-use are stated.

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