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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety and external-data profile is covered. The description adds that the payload is 'enriched' and sourced from FFIEC MDRM, which supports the openWorld hint, but it says nothing about what the tooltip contains, whether unknown codes error or return empty, or what the as_of cutoff does to results.

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?

A single short sentence with the scope front-loaded and the source attribution parenthetical kept brief. Nothing is padded, though the terseness leaves real gaps rather than being optimally informative.

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?

This is a simple two-parameter read tool with full schema coverage and annotations carrying the safety profile. However, there is no output schema, so the description should describe what an 'enriched tooltip' actually returns (name, definition, units, period applicability); it stops short of that, leaving the agent guessing at the response shape.

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% and both parameters are documented there, including the default for as_of, so the description is not needed to explain them. It adds no extra meaning such as the expected code format family or how historical definitions differ from the latest.

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 resource and scope: a tooltip lookup for exactly one Call Report column code, sourced from FFIEC MDRM. It does not distinguish itself from the sibling reference/reference_index tools, so the agent must infer which lookup to use, but the core purpose is unambiguous.

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?

There is no when-to-use guidance, no statement of what this is not for, and no routing to sibling reference tools. The only hint of usage context comes from the schema example (RCFD2170) and the as_of parameter, not from the description.

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