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

Annotations already declare read-only, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description's meaningful additions are the endpoint and the 20-credit Tier 2 cost, which is real behavioral context an agent should weigh before calling; however it says nothing about defaults, error conditions, or what the calculation assumes.

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?

A single front-loaded sentence states purpose and return contents with no filler, followed by three compact metadata lines. Efficient, though the bracketed metadata block is formulaic rather than explanatory.

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, so the description need not explain return values, and the input schema is exhaustively documented for the natal-plus-target-date body. The one gap is that it doesn't confirm the natal-plus-targetDate input shape or mention the credit cost in the prose, but overall an agent has what it needs to call this correctly.

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%, so the birth-data body, fields, and precision parameters are already thoroughly documented in the schema, including the timezone/ayanamsa/houseSystem subtleties. The description adds no parameter-level meaning beyond that, so the baseline 3 applies.

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?

Names a specific technique (annual profections) with a precise verb and enumerates the exact artifacts returned: profected Ascendant, lord of the year, activated house, monthly sub-rulers. That level of output specificity separates it cleanly from siblings such as firdaria, progressions, and primary directions without needing to open 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?

Usage is only implied: naming a distinct time-lord technique plus 'annual' signals this is the yearly profection tool, but the description never says when to choose it over astroway_prognostics_firdaria or the progression tools, nor does it state prerequisites such as needing natal birth data plus a target date. The Group/Endpoint/Cost metadata adds operational context but not selection guidance.

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