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

With no annotations provided, the description carries the full burden of behavioral disclosure. It only mentions temporal scope and coverage but does not disclose the return format, default behavior when optional date parameters are omitted, pagination, or access constraints. These gaps are significant since there is no output 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 sentences, front-loaded with the core action and scope. It is concise, but the phrase 'with the FMP Treasury Rates API' is somewhat redundant and the second sentence edges toward promotional tone. Still, there is little wasted text.

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?

The tool is simple with two optional date parameters and no output schema. The description communicates the domain and coverage, which is adequate for basic understanding, but it leaves the exact return values and default behavior undocumented. Given the lack of annotations and output schema, it is acceptable but 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?

Both parameters are documented in the schema with format and optionality, giving 100% coverage, so the baseline is 3. The description adds no extra meaning about how 'from' and 'to' affect results beyond the generic 'historical' context, so it neither helps nor hurts beyond the schema.

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 identifies the resource ('Treasury rates') and scope ('real-time and historical', 'all maturities'), which differentiates it from the many sibling market data tools. The verb 'Access' is generic, but combined with the specific resource it conveys the tool's function distinctly.

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 second sentence provides a use case ('Track key benchmarks for interest rates across the economy') but does not explicitly state when to use this tool versus alternatives or when it should not be used. This is implied usage rather than clear guidance.

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