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

With no annotations, the description carries the burden and does add useful behavior: daily files since 2022, the five-settlement-day definition, and the default date. However, it omits the return shape, how limit behaves, and whether the mention of only Nasdaq and Cboe conflicts with the nyse enum in the 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 is two dense sentences with no filler: the first defines the tool, the second lists usage modes. It is concise and front-loaded, though the second sentence is telegraphic.

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 4-parameter tool with no output schema and no annotations, the description covers the core concept but leaves out important operational details: what the returned list contains, the role of limit, and whether the nyse market option is supported despite the Nasdaq/Cboe source phrasing. Adequate for basic calls, not 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?

Schema coverage is 50%, so the baseline is 3. The description adds meaning for date (default newest), symbol (days on the list), and market (listing market), but says nothing about limit or how parameters may combine. It is helpful but does not fully compensate for the undocumented limit.

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 names the resource ('Reg SHO threshold lists'), defines the threshold condition, and states data sources with a temporal scope. It is specific enough to distinguish this from the raw fails-to-deliver tool, even though it never names a sibling.

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 explains the main query modes: one date (defaulting to the newest), one symbol, or one listing market, which gives the agent a concrete way to decide how to fill parameters. It does not explicitly mention alternatives or when-not-to-use cases, but the context is clear.

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