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

With no annotations the description carries the full burden, and it discloses useful behavioral context: each rate ships with its underlying decree, JKK maps to PP 6/2025 bands, and it flags a source discrepancy (article 18913 says Rp10.547.000 vs the Rp10.547.400 cap, pointing to the row note). That is genuine data-quirk transparency; only return format/pagination detail is absent, which is minor for a static reference table.

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?

Two sentences, front-loaded with what the tool returns, then the caveats. The second sentence is dense but each clause (JKK bands, wage cap, cross-source note) carries information an agent would otherwise get wrong.

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?

No output schema exists, but the description explains what comes back (percent rates per program with the governing decree) and warns about the wage-cap discrepancy. For a two-enum reference lookup this covers the essentials; only an explicit note on return shape 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% with both enums fully documented, so the schema already explains status and program. The description's program list merely echoes the enum rather than adding syntax or default nuance, so the 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 resource (BPJS contribution rates as percent of monthly wage) and enumerates the exact programs covered (JHT, JP, JKK, JKM, JKP, JKN) plus the decree provenance. The resource is distinct enough from siblings like get_tax_rates or get_pph21_ter that an agent can disambiguate, though it never names an alternative explicitly.

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?

Contains no when-to-use, when-not, or alternative-selection guidance. The detail about JKK bands and the JP wage cap is data content, not invocation guidance, so the agent must infer that this is the reference lookup for BPJS rate questions.

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