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

Annotations already cover read-only/idempotent safety, but the description adds substantial context beyond them: required API key with two accepted header formats, daily-limit accounting, the as_of quoting caveat, and a not-investment-advice disclaimer. This is exactly the auth/rate-limit context annotations cannot express.

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?

Front-loaded with the tool's identity, then format options, then auth requirements. The section enumeration is dense but justified for selection. Slightly long, yet no sentence is pure filler.

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 no output schema, the description still conveys content scope, format tradeoffs, auth mechanics, and rate-limit behavior. There is no output schema needing explanation, and nothing an agent needs to invoke it correctly is missing.

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% for the single format parameter, so baseline is 3. The description adds value beyond the schema by tying text to 'cheapest' and json to the 'full structured brief', giving a cost/richness tradeoff the schema enum alone does not convey.

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 (latest MacroTape market brief for the newest weekday AM/PM edition) and enumerates the content sections. An agent can distinguish it from get_brief_by_date by the 'latest' scope, though the sibling is never named 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?

Gives clear context for format selection (text = cheapest compact line, json = full structured brief), which is implicit usage guidance. However it never states when to prefer this tool over get_brief_by_date or get_sample, nor any exclusions.

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