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

Beyond the read-only and idempotent annotations, the description discloses authentication context, billing cost, and that it consumes no calculation or read units. It also clarifies that the tool returns no bond data and accepts no batch input, which is meaningful behavioral context.

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 short and front-loads the core purpose and return values. The sentence about YTM conventions, spreads, and bond prices is somewhat irrelevant for a tool that explicitly returns no bond data, though it does not significantly obscure the definition.

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 an output schema present and full annotation coverage, the description need not explain every returned field. It still gives enough context: what the tool returns, that it is authenticated, that it is free, and that it consumes no units.

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 tool has zero parameters, so there is no parameter semantics burden. The baseline score for a parameterless tool applies, and the description appropriately focuses on outputs and constraints rather than nonexistent inputs.

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 uses a specific verb, 'Return', and names the exact resources: authenticated plan, calculation/read usage, remaining quotas, and reset time. It also distinguishes itself from bond-data siblings by stating it returns no bond data and has no batch input.

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 intended use is clear from the listed outputs: checking plan, usage, quotas, and reset time. It adds useful when-not guidance by saying it returns no bond data and has no batch input, though it does not explicitly name a sibling tool to use instead for bond-related tasks.

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