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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, covering safety. The description adds value by detailing what the tool returns (issuer, value, share/principal count, percent of net assets) and that it answers specific user questions. It does not contradict any annotation and provides context beyond the structured hints.

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 moderately sized but front-loaded with the core definition, followed by usage instructions and example questions. Every sentence contributes meaning; there is no fluff. It is structured clearly, though slightly longer than strictly necessary, so a 4 is appropriate.

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 tool with no output schema, the description tells the agent what data fields are returned (issuer, value, share count, percent) and how to specify the fund and optional filters. It does not detail the exact response structure, but that is acceptable given the absence of an output schema and the tool's simplicity.

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 schema already fully documents each parameter: fund (series name or fragment), limit (count and range), and quarter (release identifier and omission behavior). The description reinforces the 'fund' parameter with examples but does not add new meaning beyond the schema, so it does not exceed the baseline.

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 reports the portfolio of a mutual fund or ETF from Form N-PORT, including largest positions with issuer, value, share count, and percent of net assets. It also gives example questions that make the tool's purpose unmistakable, and the resource is clearly distinct from siblings like nport_fund_owners or nport_holdings_coverage, even though it does not name them.

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 usage instructions ('Give the fund or ETF series name') and provides concrete example questions that indicate when to use this tool. It does not explicitly exclude alternatives or name when-not-to-use, but the examples and the focus on holdings vs. owners make the intended context clear.

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