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

Annotations already convey read-only, idempotent, non-destructive behavior. The description adds valuable context beyond that: aggregation by CUSIP, put/call flags for options, and a quarter-over-quarter diff (new/added/reduced/exited). This gives the agent a clear picture of the output shape and processing behavior without contradicting the 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 two sentences, front-loaded with the core purpose and enriched with relevant details about output composition and identifier options. It avoids filler and each clause contributes meaning. A slight sentence break at the diff explanation could improve readability, but overall it is well-structured.

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 adequately describes what the tool returns (positions, aggregation, option flags, diff) and how to specify the fund. The identifier explanation is comprehensive and the annotations cover safety and idempotency. Nothing critical is missing for an agent to call this 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 and their meanings. The description partially reiterates the identifier semantics (providing additional example fund names like 'ackman' and 'bridgewater') and clarifies the default for changes (diff vs prior quarter), but it adds limited new information beyond the schema. Baseline 3 is appropriate.

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 ('get'), a precise resource ('13F holdings'), and details what the output contains (ranked positions, CUSIP aggregation, option flags, quarter-over-quarter diff). It also explicitly lists the accepted identifier forms, making it clear this tool is for fund holdings and distinguishable from siblings like get_company or get_events.

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 states what the tool is for (retrieving a fund's latest 13F portfolio) and how to identify the target fund (name, CIK, or filer ticker). It does not name alternative tools for when this should not be used, but the domain is specific enough that an agent can infer from the sibling list. A brief exclusion note would push this to 5.

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