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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the description's bar is lower. It usefully adds billing tier (10 credits, Tier 1), the endpoint, and the group, none of which are in the annotations or schema. It says nothing about what the interpretation returns or how it is computed, but the output schema covers the return shape.

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?

Compact and front-loaded: the purpose sentence leads, and machine-relevant metadata is bracketed in a scannable block. Every element is short, though the required-parameter line is pure duplication of structured data and earns no place.

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?

An output schema exists, so return values need not be described, and the definition supplies cost, endpoint, group, and alias. Still, a 15-parameter tool with 33% schema coverage and no interpretation of the optional chart-construction parameters leaves the agent under-informed for anything beyond the default call.

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 description coverage is only 33% across 15 parameters, so the description must compensate — and it does not. Its '[Required: date, time, latitude, longitude]' line merely repeats the four required fields already declared in the schema, adding no syntax, format, or semantics for the eleven optional parameters (ayanamsa, houseSystem, fields, precision, etc.).

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 the resource and scope concretely: 'Lunar archetypes by sign and house', which is a specific interpretive output rather than a restatement of the name. It also discloses that this is an alias for astroway_psychological_modern_greene_lunar_myth, which lets the agent deduplicate. It does not, however, distinguish itself from the other Greene tools (archetypal_figures, parental_imagos, saturn_shadow) beyond the word 'lunar'.

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?

No when-to-use guidance is given. It never says which question this answers versus astroway_psyg_archetypal_figures or the other modern-psychological siblings, nor does it state prerequisites beyond the required-parameter list. The alias note routes to an equivalent tool, not to an alternative.

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