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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description does add genuinely useful non-schema context — it is a Tier 1 operation costing 10 credits — which tells an agent about billing/cost behavior. It says nothing about what the response contains or whether the reading is deterministic per invocation, so it earns partial credit only.

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?

It is compact and carries no filler, and the labeled [Group]/[Cost] tags give it a discernible structure. However the terseness is under-specification rather than disciplined conciseness — the fragment conveys symbolic flavor, not what the call does, so it does not fully earn its place.

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 only 2 optional params exist. But with 15 near-identically-named geomancy siblings, an agent still lacks the one thing it needs: confirmation that this tool produces the Carcer figure's reading and any input convention (e.g., a chart or seed) for it. The description is complete only in the metadata sense.

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% and both parameters (fields, precision) are fully documented including examples and units in the input schema. The description adds no parameter meaning at all, so the baseline of 3 for full schema coverage applies.

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 is a keyword gloss ('Restriction, confinement, isolation') that restates the title 'Carcer: Prison' rather than stating a verb+resource. It never says the tool returns a geomancy figure reading/chart, so an agent cannot distinguish it from the 15 other astroway_geomancy_* siblings beyond the figure's name. This is effectively a tautology of the title.

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, no mention of when a caller should pick Carcer over Veritas/Via/Puella or the other geomancy figures. The only contextual hint is the bracketed Group tag, which is taxonomy rather than usage direction.

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