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

The description adds substantial behavioral context that is not in the annotations: it explains the output ('Returns whether each graha currently clears the solar glare, its separation from the Sun in classical degrees of time, and the dates its visibility last changed and next changes'), the deliberate absence of a time field ('heliacal visibility is a once-a-day verdict read at that day sunrise or sunset'), and the latitude restriction with the reasoning that beyond 60 degrees the rule breaks down. This goes beyond the simple readOnly/destructive annotations.

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 first sentences are front-loaded with purpose and outputs, which is good. However, the description ends with a keyword-stuffed line: 'Graha asta API, Guru Asta Shukra Asta dates, heliacal rising calculator, planetary combustion muhurta.' This adds no informational value for an AI agent and makes the description feel padded. Overall it is reasonably concise but not every sentence earns 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?

Despite having no output schema, the description provides a complete mental model of what the tool computes, its key outputs, the rule used, the location-awareness distinction, and the practical muhurta use case. It also explains the latitude constraint and the no-time-field design decision. For a complex astronomical tool, this is sufficient for an agent to select and invoke it without ambiguity.

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 100% with detailed descriptions for every parameter, so the baseline is 3. The description adds extra semantic value by explaining why there is no time field (parameter 'date' is a daily verdict), why latitude is restricted (parameter 'latitude' affects ecliptic-horizon angle), and why timezone matters. This pushes the score above baseline, though the schema itself remains the primary source.

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 uses a specific verb ('Calculate') and clearly defines the resource ('heliacal rising (udaya) and setting (asta) of the six visible grahas'), including the governing rule ('Surya Siddhanta rule'). It differentiates itself from a birth chart combustion flag by emphasizing location awareness, making the purpose distinct from 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 provides clear context for when to use the tool: 'the calculation behind Guru Asta and Shukra Asta, the periods classical muhurta withholds marriage and other auspicious ceremonies.' It also gives an explicit when-not: 'Unlike a birth chart combustion flag it is location aware', which tells the agent this should be used instead of a generic combustion flag for location-dependent visibility. However, it does not name a specific alternative sibling tool by name, so it stops short of a 5.

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