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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds the 2027 default but does not say how deterministic, how long, or in what form the reading is returned, which matters for a tool with no output schema.

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 sentences: the first front-loads what the reading produces, the second lists triggering questions. Efficient, with no filler, though the question list runs slightly long relative to the substantive 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?

The description conveys the reading's thematic scope, which partly substitutes for the missing output schema, but it leaves the 'gender' parameter's role and the optional 'birth_time' unexplained, and gives no sense of output shape or length for a 4-parameter tool.

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 75%, so most parameters are already documented. The description adds the default-year behavior (2027) but says nothing about the purpose of 'gender' or when to supply the optional 'birth_time', leaving those to the schema.

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?

Names the specific resource (year-ahead reading) and specifies what the output covers: main themes, where change or a bond forms, and life chapter, anchored to a birth date. It is clearly distinct from the siblings (birth_time_reading, compatibility_reading) by subject matter, though it never explicitly contrasts with them.

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?

Provides concrete example user questions ('Is 2027 my year?', 'When will things get better?') plus love and career timing, which gives an agent clear triggering conditions. It stops short of any when-not-to-use guidance or naming a sibling as the alternative for overlapping cases.

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