Sabian Symbols

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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the core safety profile is covered. The description adds operationally useful context beyond that — credit cost (Tier 1), endpoint, group — but says nothing about output shape, null handling, or how symbols are derived for edge-case degrees.

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?

One sentence of prose follows the metadata block, with no filler and the purpose front-loaded. The bracketed Group/Endpoint/Required/Cost lines are compact and each carries distinct information.

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 simple single-parameter lookup with an output schema, the definition covers purpose, required input, and cost, which is enough to invoke it correctly. The remaining gap is that the accepted longitude range and behavior on the rudhyar_symbolic_degrees sibling are unaddressed.

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 carries the burden: it correctly identifies the parameter's content as ecliptic longitudes, which the bare array-of-numbers schema does not. However, it omits the valid degree range, whether 360 max items correspond to one item per degree, and how null items are treated.

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 verb ("Return") and a specific resource ("the Sabian symbol (Dane Rudhyar)") plus the input unit ("ecliptic longitude"), so an agent knows exactly what it produces. It does not differentiate itself from a plausibly overlapping sibling such as astroway_psychological_modern_rudhyar_symbolic_degrees, which keeps it below a 5.

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 description never says when to use this versus alternatives, nor when not to. The only usage signal is the "Required: longitudes" line, which restates the schema rather than giving guidance.

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