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

Annotations already declare readOnly, idempotent, openWorld and non-destructive. The description adds genuine context beyond them: the data source (SEC Form N-MFP monthly portfolio filings), the default behavior when period is omitted (most recent published month), and the returned fields. No auth or rate-limit disclosure, but the safety profile is fully covered.

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?

Front-loaded with the core operation, then the disambiguation, then return fields and example questions. Every sentence contributes, though the trailing list of example queries is slightly redundant with the earlier explanation.

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 3-parameter read tool with no output schema, the description is nearly self-sufficient: it names the source, the return fields (fund, family, title, category, maturity dates), and the period default. It does not cover pagination past the schema's limit bound, but that is documented in the schema.

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 coverage is 100%, so the schema already documents all three parameters. The description nonetheless adds useful semantics for issuer — it accepts a name, a fragment, or a 9-character CUSIP, with worked examples — and clarifies the period default. Slightly above the baseline-3 case for a fully documented schema.

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 (find holders) and resource (US money market funds holding a given issuer's paper), with the scope inverted explicitly against the sibling nmfp_fund_holdings ('the reverse of a fund fact sheet, which makes you name the fund first'). An agent can distinguish it from nmfp_fund_holdings 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?

Clearly frames the query direction (issuer → funds) and gives concrete question shapes it answers ('which money market funds are exposed to this issuer'). It implies the alternative (fund-first lookup) but never names nmfp_fund_holdings directly, so sibling routing is inferred rather than stated.

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