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

Annotations already declare the full safety profile (readOnlyHint, idempotentHint, destructiveHint false, openWorldHint false), so the bar is lower. The description adds the cost/group metadata ('20 credits, Tier 2'), which is genuine behavioral context beyond the annotations, but says nothing about the response shape or limits.

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-load the core action, followed by compact group and cost tags. Nothing is padded or redundant, though the optional-aspects clause is doing little work.

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 15-parameter tool with only 33% schema coverage, the description omits any guidance on inputs or configuration even though an output schema covers return values. An agent has no help navigating the many optional parameters or distinguishing this from the midpoint_trees sibling.

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 is expected to compensate and does not. It never mentions the required date/time/latitude/longitude inputs or the many configuration knobs (ayanamsa, houseSystem, zodiacType, precision), leaving half the schema undocumented anywhere.

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 states a specific verb and resource: 'Calculate all planetary midpoints and their zodiac positions,' plus an optional mode ('midpoint aspects to natal points'). It is clear on its own but never distinguishes itself from the near-identical sibling astroway_aspects_midpoint_trees, so an agent cannot tell which one to reach for from the text alone.

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 only usage signal is 'Optionally include midpoint aspects to natal points,' which describes an internal option rather than when to choose this tool over astroway_aspects_midpoint_trees or other aspects tools. No preconditions, exclusions, or alternative routing are given.

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