Midpoints

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so safety is covered. The description adds genuinely useful operational facts not in annotations: the POST endpoint, the required coordinate/time inputs, and the 20-credit Tier-2 cost. It stops short of describing output shape or how the optional aspects toggle behaves.

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 tight sentences front-load the core computation, followed by bracketed metadata for group, endpoint, required inputs, and cost. No padding; the metadata lines are scannable 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?

An output schema exists, so return values needn't be explained, and cost/endpoint/required inputs are given. However, for a 13-parameter tool with 23% schema coverage, the description leaves the optional-aspects control and the majority of optional parameters unaddressed, which is a real gap for correct invocation.

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 23% across 13 parameters, so the description must compensate and mostly doesn't. It lists the four required inputs (date, time, latitude, longitude) but says nothing about city, name, cosmogram, houseSystem, zodiacType, ayanamsaId, or the timezone/timezoneOffset interplay that the schema only partially explains.

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 names a specific verb and resource: 'Calculate all planetary midpoints and their zodiac positions', plus the optional aspect dimension. It distinguishes the tool from generic aspect tools implicitly, though it never names the nearest siblings (astroway_aspects_midpoint_trees, astroway_cosmobiology_midpoint_pictures) that could be confused with it.

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 says midpoint aspects to natal points can 'optionally' be included, but never says which input controls that option, nor when to pick this over midpoint_trees or the cosmobiology midpoint tools. No prerequisites, no exclusions, no alternatives.

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