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

Annotations already cover read-only, idempotent, open-world and non-destructive behavior. The description goes beyond them by disclosing the 15-holding ceiling and, importantly, describing the return payload: per-standard compliance share, failing holdings, and a combined dividend purification ratio.

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?

Two sentences, the purpose leading and return details following — well front-loaded with no filler. The second sentence is dense but every clause (standards count, compliance share, failures, purification ratio) adds 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?

With no output schema, the description usefully enumerates the return shape, and annotations cover the safety profile, leaving few gaps. It does not state error behavior past the 15-holding limit or how weighting affects the results, which would round it out.

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?

Single parameter with 100% schema description coverage, so the ticker:weight syntax is already documented in the schema. The description only adds the aggregate cap (15 holdings), which is marginally useful but not beyond-schema meaning for 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?

States a specific verb (Screen) and resource (a whole portfolio), and the phrase 'whole portfolio' inherently distinguishes it from the sibling screen_company, which presumably handles one company. It also quantifies scope with the 15-holding cap.

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?

Usage is implied by the 15-holding cap and the portfolio-level framing, but the description never explicitly says when to use this versus screen_company or list_standards, nor what happens past 15 holdings. Adequate context, no explicit routing guidance.

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