Daily Horoscope

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

With no annotations at all, the description carries the full burden, and it does disclose the important default behavior that an omitted 'sign' returns all twelve signs rather than nothing or an error. It says nothing about permissions, rate limits, or freshness of the data, which are the remaining behavioral unknowns.

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?

Two short sentences, front-loaded with the core purpose and then the parameterized behavior. No filler, no repetition of the title.

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 single-parameter read tool with an output schema (so return values need no explanation), the description covers the one thing the schema leaves ambiguous: what happens when 'sign' is omitted and what format values the parameter accepts. Only the daily/weekly/monthly scope distinction is left implicit.

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 0%, so the description must compensate, and it does: it specifies the accepted format (English, lowercase) and supplies a concrete example ('leo'), which the schema's bare string/null anyOf does not convey. Noting the null default's meaning also fills a real gap.

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+resource: it returns the daily horoscope, either for all twelve signs or for one named sign. 'Daily' plus the tool name cleanly separates it from weekly_horoscope and monthly_horoscope, but those siblings are never named, so the differentiation relies on the reader's inference.

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?

It clearly states the two operating modes and which one applies: omit 'sign' for all twelve signs, supply 'sign' for a single sign. That is genuine when-to-use context, though no exclusions or explicit sibling alternatives (weekly/monthly) are mentioned.

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