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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so safety is covered. The description adds one genuinely useful disclosure — 'Dates can be extended by notification' — warning that returned dates may differ from official amended deadlines. Beyond that it adds nothing about scope, freshness, or the subscribe link's purpose.

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?

Three short, front-loaded sentences with no filler; the purpose lands first. Saved from a 5 only because the enum restatement consumes most of the word count without adding meaning.

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 needn't be explained, and the caveat about notification extensions is valuable. However, for a tool with a 0%-documented two-parameter schema, the description leaves the count parameter and the meaning of 'normal' versus extended dates unexplained.

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 0%, so the description must carry parameter meaning and it largely does not. The calendar enum values are merely restated (already visible in the schema) and the 'count' parameter — 1 to 24, undocumented anywhere — is never mentioned or explained.

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+resource: 'Next normal due dates from a compliance calendar', and names the calendar families it covers. An agent can tell this is a read-lookup for Indian tax/GST deadlines and it is not easily confused with any sibling (calculate_gst, check_gst_registration, etc.).

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 implied by 'compliance calendar' and 'next due dates', but the description gives no explicit when-to-use or when-not-to-use guidance and doesn't point to a related sibling. It also doesn't say a 'calendar' value is required, though the schema does.

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