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

No annotations exist, so the description carries the full behavioral burden. It discloses cost ('Free') and scope ('national and banking'), but says nothing about return shape (list of dates? names?), ordering, timezone, or whether Carnival-style movable feasts depend on year. This is thin for a tool with zero annotation coverage.

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?

One compact sentence, front-loaded with the resource and followed by clarifying examples and a cost note; no wasted clauses. The 'Free.' fragment and a parenthetical example list are slightly informal but still earn their 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 trivial one-parameter tool this covers what is fetched and that it is free, and the schema covers the accepted year range. However, with no output schema and no description of the return structure, an agent still does not know what it will receive back, leaving a real gap.

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 coverage is 0%, but the single parameter is fully typed with an explicit 1990–2100 range in the schema. The description only implies 'year' via 'for a year' and adds no new semantics (e.g., behavior outside the range, format). Marginal value over the schema, so a middle score fits.

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?

The description names a specific resource (Brazilian national and banking holidays for a year) and even enumerates the notable entries it covers (Carnival, Good Friday, Corpus Christi, Nov 20), which sets it apart from siblings like business_days and bank_lookup. The verb is only implicit ('returns'), and it never explicitly contrasts itself with business_days, so it falls short of a 5.

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 when-to-use or when-not-to-use guidance and no mention of alternatives; an agent must infer that this is the holiday-list tool versus business_days (working-day math). 'Free' hints at cost/auth but is not usage routing. Only implied usage is present, not stated.

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