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

Annotations already declare this a read-only, idempotent, non-destructive, closed-world computation, so the safety profile is covered. The description adds a genuinely useful behavioral fact not in the annotations: the 50-credit / Tier 3 cost, plus the caveat that the chart is cast on the sidereal solar return and can land on a different ascendant than a tropical solar return. It still says nothing about auth requirements or rate limits.

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, front-loaded with the purpose, and the [Group]/[Endpoint]/[Cost] metadata is compact. The age-indexed hour-gap series (0.4 h at 1, 3.3 h at 10 … 17.2 h at 50) is longer than an agent strictly needs and edges toward exposition, but it does quantify a real divergence.

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, annotations cover the safety profile, and the schema documents every parameter, so the description is not required to explain returns or fields. It covers what the chart is and the sidereal-return nuance; the only substantive omission is guidance on how this differs from the other varshphal-family sibling.

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 the nested schema already explains timezone, timezoneOffset, ayanamsa, houseSystem letters, year, and the entryLatitude/entryLongitude pairing in detail. The tool description adds no parameter-level meaning beyond implying the sidereal framework; baseline 3 is appropriate when the schema carries the whole load.

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 both the technique and the artifact: 'The Tajika annual chart for one year of life,' which is a specific resource an agent can match to a request. It does not, however, distinguish itself from the sibling astroway_vedic_lal_kitab_varshphal, which is also an annual (varshphal) chart produced by a different school, so the agent has no textual basis for choosing between 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?

Usage is only implied: an agent can infer 'use this when you want the Tajika annual chart for a given year' from the opening sentence, but there is no explicit when-to-use, when-not, or routing note. With a near-identical sibling (lal_kitab_varshphal) in the list, the absence of an explicit alternative is a real gap.

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