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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered structurally. The description adds two pieces of context the schema cannot convey: the billed cost (10 credits, Tier 1) and the HTTP endpoint. That is useful, but it says nothing about auth requirements, rate limits, or result granularity beyond the vague 'high-level'.

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 single guidance sentence is front-loaded and waste-free, and the bracketed metadata blocks are scannable. Offsetting that, the '[Required: ...]' block duplicates information already in the input schema rather than earning its place, and the terse bracket style reads as a data dump rather than 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 the description is correctly relieved of explaining return values. For a 15-parameter tool with low schema coverage, though, the definition is thin: it supplies cost and endpoint but no guidance on choosing among the crowded business_* family, and half the parameters remain undocumented in either place. Minimum viable, clearly lacking.

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% across 15 parameters, so the description carries a real compensation burden and fails to meet it. The '[Required: date, time, latitude, longitude]' line merely repeats the schema's required array verbatim and adds no meaning, while the eleven optional parameters (zodiacType, houseSystem, fields, precision, etc.) that lack schema descriptions get no explanation here either.

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 resource (high-level expansion guidance) but the verb and scope are vague — 'guidance' could mean almost anything, and it never says what the tool actually computes or returns. It does gesture at a boundary by telling the agent it is NOT the source of concrete windows (pair with /transits), which is better than nothing. However it does nothing to distinguish itself from the ten-plus other astroway_business_* siblings.

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?

'Pair with /transits for actual windows' implies this tool is the qualitative/complementary half of a two-call pattern, which is genuine usage guidance. But there is no statement of when to prefer this over astroway_business_electional_day or astroway_business_risk_profile, nor any prerequisites or exclusions. Usage is implied rather than specified.

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