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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered. The description adds genuinely useful operational context (endpoint, Tier 2 cost of 20 credits) not present in annotations, but says nothing about output shape or what a 'midpoint tree' actually resolves to.

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?

Front-loaded with the core action in the first clause, followed by compact structured metadata lines. Nothing is padded, though the group/endpoint/cost footer is boilerplate rather than task-relevant prose.

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. Annotations cover the safety profile. However, for a domain-specific Uranian technique whose sibling tool (astroway_aspects_midpoints) is nearly identical, the description leaves the agent without enough to know when this tool is the right pick.

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 100%, so the schema already documents the body, orb, fields and precision parameters. The description's mention of 'within a given orb' loosely points at the orb parameter but adds no syntax, defaults, or range detail beyond the schema. Baseline 3 is appropriate.

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 ('Calculate') and a well-scoped resource ('Uranian midpoint trees and planetary pictures (symmetries) for each focal planet within a given orb'). This is more than a restated name, but it does not distinguish itself from the very close sibling astroway_aspects_midpoints, so the agent cannot route between them from the description 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?

There is no when-to-use guidance and no named alternative, despite a near-identical sibling (astroway_aspects_midpoints) that would be the natural confusion point. The only usage context provided is a group/endpoint/cost footer, which is operational metadata rather than selection guidance.

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