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

The readOnlyHint and destructiveHint annotations already cover safety. The description adds useful behavioral detail beyond that: the month is simulated from current date when omitted, all nine planets are always covered, and starting positions for the month are included. This properly extends the annotation-only picture by default and scope behavior.

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?

The description brings key information up front: what the tool returns, which planets are covered, and what the includes at the start. The only mild weakness is the final SEO-style sentence 'Monthly planetary transit API, gochar calendar, rashi parivartan dates,' which repeats synonyms rather than earning 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?

For a six-parameter tool with no output schema, the description covers the primary return content, default time behavior, sign-change semantics, planet coverage, and use cases. It does not fully describe the output shape or how transitions are represented, which would have been helpful given the absence of an output schema, but it is still sufficiently complete for safe selection and invocation.

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 complete, and the schema documents all six parameters with defaults, types, and enums. The description only adds the 'omit year/month' default behavior, which the schema already states, so it does not add meaningful parameter semantics beyond the schema's baseline.

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 states a specific verb and resource: get all planetary sign (rashi) changes for a month, and then clarifies what that means with planet transitions. It also names the full 9-planet Vedic roster and the inclusion of month-start positions, so the tool's scope is unmistakable even among many sibling tools.

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?

The description gives clear context for when to use it: transit prediction, monthly horoscope generation, and muhurta planning. It also explains the useful 'omit year/month' behavior for keeping a gochar calendar current. It does not explicitly name sibling alternatives or say when *not* to use this tool, so it falls just short of full routing guidance.

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