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

Annotations already mark the tool as read-only and non-destructive, and the description adds beyond that: it discloses the output structure (largest holdings, share counts, market values, percent of portfolio, total value, position count), default/max results, and the ambiguity handling behavior ('ambiguous partial returns candidate CIKs instead of selecting silently'). This is useful context not available from annotations or schema.

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 consists of two well-structured sentences. The first sentence defines the tool's function and outputs; the second provides usage guidance. Every phrase contributes essential information—no filler, no redundancy, and the most critical details are front-loaded.

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 carries the burden of explaining returns, and it does so thoroughly: it lists the specific data included (share counts, market values, percent of portfolio, total value, position count). It also covers defaults (20, max 500), ambiguity resolution, and the predecessor tool. For a read-only tool with four well-documented parameters, this is contextually complete.

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?

The schema descriptions cover all four parameters (100% coverage), providing clear field-level details. The main description adds contextual meaning around the 'largest tracked holdings' concept and confirms default/max limits, which helps understand the offset/maxResults parameters without duplicating schema text. It adds value beyond the schema rather than merely restating it.

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 clearly states the tool 'View the stock portfolio of a specific institutional investor (fund manager) from their SEC 13F-HR filing,' with a specific verb and resource. It enumerates the output scope (largest holdings, share counts, market values, portfolio total) and distinguishes itself from search tools like SearchInstitutions by pointing users to resolve ambiguous names first.

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 explicitly tells users when to use this tool ('Use this to understand what stocks a particular fund manager or institution is investing in') and instructs them to use SearchInstitutions first when the name is ambiguous. While it does not mention alternatives like GetFundHoldings or GetTopHolders, the provided guidance is clear and actionable for common scenarios.

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