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

Annotations already declare readOnly, idempotent, non-destructive, and non-open-world, so the safety profile is covered. The description adds the credit cost (Tier 1) and group label, which annotations omit, but says nothing about the compact-mode behavior driven by the 'fields'/'precision' parameters.

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?

Compact and front-loaded: the operation and its scope lead, with the group/cost tags clearly bracketed as metadata. No filler prose, though the metadata blocks add length without aiding invocation.

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 return values need no explanation, and annotations cover safety. However, the required inputs are undocumented and compact mode is unmentioned, leaving an agent to guess at input formats for a 5-parameter calculation tool.

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 only 40%; the three required parameters (name, date, year) carry no schema descriptions at all, and the description supplies no meaning for them. Only 'fields' and 'precision' are documented in the schema, so the description fails to compensate for the coverage gap.

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 verb ('Calculate'), a precise resource ('Personal Year number'), and the scope ('for a given calendar year'), plus the system ('Vedic'). The system tag distinguishes it from the chaldean/kabbalistic/pythagorean personal-year siblings, though it never explicitly contrasts them.

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?

There is no guidance on when to choose this over the many sibling personal-year tools (chaldean, kabbalistic, pythagorean, numk/numks/nump). The system tag implies the intended domain but leaves the selection decision entirely to inference.

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