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

Annotations already establish readOnly, idempotent, non-destructive, non-open-world behavior, so the bar is lower. The description adds genuine context beyond them: it flags that alternative full derived charts remain 'explicitly unvalidated' and that output includes a reuse warning, which tells the agent about result trustworthiness.

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 front-loaded sentences with no filler; the core comparison and the anchor list come first, and the validation caveat is placed last where it functions as a scope limit. Slightly dense with an inline enumeration, but every clause carries information.

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?

With an output schema present, the description need not explain return values, and it correctly focuses on scope and validation limits instead. It is close to complete for a read-only comparison tool, missing only convention-selection guidance and how the mutually exclusive location inputs behave.

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 0%, so the description must carry parameter meaning. It adds semantics for two domain-specific inputs ('one topic' and the selected alternative ayanamsa projections), but says nothing about the location parameters (place vs latitude/longitude/timezone/timezoneOffset), date/time format, or the name field; the remaining eight parameters are left entirely to inference.

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 and resource: compares Lahiri against alternative ayanamsa projections for one topic, and enumerates the derived anchors it tracks (Lagna, topic lord, karaka, sign, house, Nakshatra). That is enough to distinguish it from calculate_ayanamsa_chart or compare_traditions without opening a schema, though it never names a sibling explicitly.

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 implied rather than stated: the phrase 'marks when a Lahiri judgment must not be reused' hints at the scenario (checking whether a convention switch invalidates a reading), but there is no explicit when-to-use, when-not-to-use, or named alternative among the many analyze_*/compare_* siblings.

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