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

Annotations already declare readOnly, idempotent, and non-destructive behavior, so the safety profile is covered. The description adds valuable behavioral context beyond annotations: results are ranked by position size, come from N-PORT filings, and include sponsor, position value, share/principal count, and percent of net assets. No contradictions exist between the description and annotations.

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 front-loaded with the core purpose and includes useful illustrative examples. It is somewhat long with repeated example phrasings, but every major element—input, output fields, ranking, and source—earns its place. It remains readable and scannable without excessive verbosity.

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 compensates by explicitly listing the returned fields (fund, sponsor, position value, share/principal count, percent of net assets) and accepted input forms. It also explains the data source and ranking behavior. Minor omissions such as default limit behavior are already handled by the input schema, so the tool is sufficiently complete 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 schema already documents all three parameters. The description reinforces that 'security' can be a ticker, company name, or CUSIP and lists return fields, but it does not add new meaning beyond the schema for 'limit' or 'quarter'. The baseline score of 3 is appropriate because the schema carries the parameter documentation burden.

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 purpose: identify mutual funds and ETFs holding a given stock or bond, ranked by position size, sourced from SEC Form N-PORT filings. It clearly distinguishes itself from a 'fund fact sheet' and specifies accepted inputs (ticker, company name, CUSIP), making it immediately identifiable and distinct from sibling tools like nport_fund_portfolio.

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 concrete use cases ('which ETFs hold the largest positions in NVDA', 'what funds own this corporate bond') and explicitly frames the tool as the reverse of a fund fact sheet, implying when to choose it over a fund-first lookup. It does not name sibling tools explicitly or state exclusion criteria, but the context is clear enough for an agent to route correctly.

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