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

With no annotations, the description carries the full behavioral burden, and it does disclose the return content (profile plus a 30-day spread path), which is genuinely useful. However, it says nothing about failure behavior when the CUSIP is not an index constituent, data freshness, units/frequency of the spread path, or any access constraints.

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 sentence with the verb, scope, and key parameter front-loaded and no wasted wording. Nothing is buried or repeated.

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 one-parameter read tool this is nearly adequate, and the description at least characterizes the returned data. With no annotations and no output schema, though, an agent still lacks the return structure, spread-path units/tenor convention, and behavior for non-constituent CUSIPs.

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 the schema already defines the 9-character CUSIP pattern with the identical example, so the description adds no meaning beyond it. Baseline 3 is appropriate for a single fully-documented parameter.

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 gives a specific verb ('Get') and a precisely scoped resource: the profile and 30-day spread path of a single constituent bond, keyed by CUSIP. It is clearly distinguishable from index-level siblings like ncsx_levels or ncsx_weekly, though it never names those siblings explicitly.

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 use case is implied by 'one constituent bond by CUSIP' — drill into a single name rather than an index aggregate — but there is no explicit when-to-use versus alternatives and no stated preconditions. An agent can infer the routing, but it must do the inferring itself.

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