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 genuinely useful operational context beyond that: a cost of 20 credits (Tier 2), the POST endpoint, and the four required date/time/coordinate inputs. It stops short of describing determinism or any output characteristics, but the credit cost disclosure is a meaningful addition.

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 prose is a single front-loaded sentence that names the tool's scope before any metadata, and the bracketed Group/Endpoint/Required/Cost block is scannable and each line carries distinct information. No redundant or filler sentences, though the required-fields line duplicates the schema's own required array.

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 the annotations plus cost line cover the safety and budget concerns. However, for a 15-parameter tool with only 33% schema coverage and five horary siblings, the description omits both the alternative-tool routing and any explanation of the sidereal/house-system/timezone parameters that change the result.

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%, so the description must carry weight — yet it only restates the four required fields (date, time, latitude, longitude), which the schema's 'required' array already provides. Eleven optional parameters, including the semantically important timezone, timezoneOffset, houseSystem, ayanamsa/zodiacType and the compact-mode fields/precision options, receive no explanation in the description even though they materially affect the diagnostic.

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 ('Run a full horary radicality diagnostic') and enumerates the checks it covers (early/late ASC, Via Combusta, Saturn in 7th, considerations before judgement), which is far more informative than the title alone. It does not, however, explicitly distinguish itself from the sibling horary tools such as astroway_horary_horary or astroway_horary_via_combusta, so an agent must infer that this is the composite diagnostic.

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 explicit when-to-use guidance: nothing says this should be run before judgement, nor whether the chart should first be cast with astroway_horary_horary. The 'radicality diagnostic' framing implies a pre-judgement check, but the agent is left to infer the workflow and the relationship to the five sibling horary tools.

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