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

Annotations already declare read-only/idempotent/non-destructive, and the description adds real behavioral context beyond them: the exact computation rule ('move one day at a time; decrement only on status.is_working_day=true'), coverage limits, the Feb 10 exclusion rationale, and a caveat that lunar dates may be revised by later official notice.

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?

Usage guidance is correctly front-loaded, but the block is padded with a full 'Outputs' enumeration that duplicates the existing output schema and an 'Inputs' line that duplicates the schema, so 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?

For a tool with an output schema and full annotations, the description covers everything else an agent needs: when to use and when not, the computation rule, argument example, and a direct REST fallback path with a warning not to guess other /api/* routes.

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% and both parameters carry descriptions plus examples, so the baseline is 3. The description's 'Inputs' line and JSON example merely restate the schema, adding no meaning such as offset sign conventions beyond what the schema already says ('signed offset; start date excluded for non-zero offsets').

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 pair (adds or subtracts) and a scoped resource (Bangladesh authority-scope working days), and the country qualifier is exactly what separates it from the ~60 add_*_working_days siblings. An agent can pick it out of the family without opening the 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?

Explicit 'use this when' plus a detailed 'do not use this when' that names the excluded schedule scopes (private-employer, bank, school, industrial-zone, essential-service, regional) and a specific date exclusion. It does not, however, route to the nearest siblings (count_bd_working_days, check_bd_working_day) for count/check needs, so the alternative-selection guidance is incomplete.

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