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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=false, destructiveHint=false, so the safety profile is covered. The description adds scope constraints (2026-only, federal jurisdiction, exact range) that go beyond the annotations. No auth/rate-limit detail, but this is a stateless read computation so the gap is minor.

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?

Front-loaded with the when-to-use line and clearly labelled sections (Inputs, Outputs, Formula, Fallback, Docs). It is somewhat long and the Outputs list duplicates the existing output schema, plus the formula line is low-value, but the structure keeps it navigable.

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 already exists, yet the description still covers scope limits, inputs, an example call, and a REST fallback path. Nothing an agent needs to invoke this correctly is missing.

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 schema already documents all four parameters and their defaults. The description restates the inputs and gives a complete JSON example, but adds no semantic meaning the schema lacks. 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?

States a specific verb (count), resource (UAE federal-government working days) and scope (2026, federal only), and explicitly distinguishes itself from local-government/private/bank/school/future-year calendars. An agent can separate it from the many country-specific count_* siblings without opening a 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?

Gives explicit when-to-use ('when you need an auditable UAE federal-government workday count for 2026'), explicit when-not ('local-government, private-employer, bank, exchange, school or future-year calendar'), and directs the agent to call it directly rather than answer from memory. Strong routing guidance.

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