Midpoints

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

Annotations already indicate the tool is read-only, non-destructive, and idempotent. The description adds that it calculates midpoints and optionally includes aspects, consistent with annotations. However, no additional behavioral details (e.g., output format, pagination, or rate limits) are provided beyond what annotations cover.

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?

The description is short (two sentences) and front-loaded with the key purpose. However, it includes non-essential formatting like group and cost labels. The example is useful but could be integrated more clearly.

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?

Given the tool has 11 parameters, no output schema, and 0% parameter documentation, the description is severely incomplete. It only states what is calculated but not how to use the parameters or what the output structure is. The example provides minimal context.

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 0%, meaning no parameter descriptions exist in the input schema. The description does not explain any of the 11 parameters (date, time, timezoneOffset, etc.). The example request body shows values but lacks explanation of purpose or constraints.

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 clearly states the tool calculates all planetary midpoints and zodiac positions, with an optional inclusion of midpoint aspects to natal points. This is specific and distinguishes it from sibling tools like 'aspects' or 'midpoint_trees'.

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?

Usage is implied by the tool's name and description (if you need midpoints, use this), but there is no explicit guidance on when to use it versus alternatives, or when not to use it. No mention of excluded cases or references to sibling tools.

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