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

Annotations declare readOnlyHint=false, destructiveHint=false and openWorldHint=true but say nothing about cost. The description adds the Tier 5 / 250-credit price and an explicit instruction to confirm with the user first, which is real behavioral context an agent needs before invoking. It does not disclose latency or that the output is long-running, but the cost disclosure is the material one.

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?

Three tight sentences plus a group/cost tag block, front-loaded with what the tool produces before the input list. The 'Inputs:' enumeration is slightly over-compressed because it presents an incomplete parameter list as if it were complete, but there is no filler.

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?

For a complex, nested-chart, non-readonly generation tool this covers the essentials: what is produced, the key inputs and defaults, and the cost/confirmation requirement. With an output schema present it need not describe return values, though the compact-mode params and the relationship to sibling report tools remain unexplained.

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 43%, and the description compensates well for the important gaps: it states that 'year' defaults to the next year (the schema has no default for it) and that 'length=long' is what produces a full annual report. It omits the compact-mode parameters (fields, precision) and says nothing about tone or language semantics, so coverage is partial but the highest-value parameters are clarified.

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+resource (long-form annual report) and describes the synthesis: natal context plus the year's major outer-planet transits clustered by month. That is enough to distinguish it from astroway_reports_ai_monthly_narrative, but the nearby sibling astroway_reports_transit_yearly and the other *_narrative AI reports are never named, so the agent must infer the boundary.

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 gives operational guidance ('confirm with user before invoking' for a 250-credit call) and a parameter-level hint ('use long for full annual report'), which is genuinely useful. However, it never states when to choose this over astroway_reports_ai_monthly_narrative or astroway_reports_transit_yearly, so 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.