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

Annotations already cover safety (readOnly, idempotent, non-destructive), so the bar is lower. The description adds valuable context: the scope of the calculation (120-year cycle), the output includes Mahadasha/Antardasha periods and active dates, and a direct link to the interactive calendar. It does not mention rate limits or authentication, but for a read-only calculation tool this is sufficient.

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 is front-loaded with the core purpose, then lists required inputs, then output details. It is two sentences but dense; every clause adds value. Minor improvement: separating the output list into a bullet could aid scanning, but overall efficient.

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?

Output schema exists, so return values need not be explained. The description covers the domain, required inputs, defaults, and output nature. It omits how aliases are resolved and the significance of target_date, but these are arguably edge cases. For a complex astrological tool, it is nearly complete.

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%, so the baseline is 3. The description adds meaning by stating defaults ('time' defaults to '12:00'), format expectations (YYYY-MM-DD, HH:MM), and that city is required. However, it does not explain aliases (birth_city, birth_date) or the role of target_date, user_prompt, and country, which are only described in 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?

States a specific verb ('Calculate') and resource ('classical Parashara Vimshottari Dasha planetary timeline'), and names the sibling-adjacent capability ('/dasha slash command'). An agent can distinguish it from calculate_chart, get_horoscope, and get_yogas without opening any schema.

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?

It specifies required inputs (birth date, time, city) and default behavior, which implies the when-to-use context. However, it does not explicitly name alternative tools (e.g., calculate_chart for natal charts, get_horoscope for daily predictions) or state when-not-to-use this one.

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