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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds the credit cost (Tier 2, 20 credits) and notes the response includes star details and aspect type, but says nothing about the missing orb control it advertises, nor about output volume 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 tight sentences with the core operation front-loaded, plus compact group and cost metadata. No filler, though the cost/group lines are boilerplate rather than definitional content.

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 explained, and annotations cover safety. But with 15 inputs at 33% schema description coverage and no mention of the required birth-data parameters or sidereal/house options, an agent must reconstruct the calling contract almost entirely from the schema.

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 coverage is only 33% across 15 parameters, so the description carries more burden than it does. It mentions 'specified orb' even though no orb parameter exists in the schema, and it never explains the required date/time/latitude/longitude quartet, zodiacType, houseSystem, or the ayanamsa options.

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?

Specific verb+resource: 'Calculate conjunctions between natal planets and fixed stars within a specified orb,' which an agent can distinguish from the sibling astroway_aspects_fixed_stars_catalog (a star listing) without opening either schema. However, no sibling is named explicitly, so differentiation relies on inference.

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, no prerequisites, and no alternatives named. 'Within a specified orb' hints at a narrowing input, but the description never says when this tool should be preferred over other aspect tools such as astroway_aspects_parallel_aspects or the fixed-star catalog.

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