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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description adds valuable behavioral detail: values 'normally use report-date closing prices, may fall back to filer values, and can be zero when unavailable.' This goes beyond the annotations by explaining data quirks the agent needs to anticipate.

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?

Three sentences with no redundancy. The main function is front-loaded, followed by ranking behavior, value caveats, and a usage tip. Every sentence earns its place.

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?

The description covers input constraints, ranking logic, value fallback behavior, and the shared-position threshold. Since there is no output schema, it would be helpful to state the exact returned fields explicitly, but the description gives enough shape (stocks ranked by holder count and combined value) for an agent to invoke 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 the baseline is 3. The description reinforces the minInstitutions behavior and institution count range, but adds little beyond what the schema already states for each parameter. No significant new parameter-level meaning is introduced.

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 ('Combine'), a clear resource ('2-25 institutions' 13F portfolios'), and the output behavior ('Ranks stocks by holder count, then combined value'). This distinguishes it from related siblings like GetInstitutionPortfolio (single institution) and CompareInstitutionPortfolios (comparison rather than consensus aggregation).

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 clearly indicates the use case: aggregating 2-25 institutions' holdings and finding shared positions via minInstitutions. It does not explicitly name alternatives or state when not to use the tool, but the focus on consensus across multiple filers provides clear context for selection among sibling tools.

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