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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so safety and side-effect behavior need no restating. The description adds genuine context beyond that: data provenance (monthly PFR Portal PPK bulletin / PPK Register kept by PFR), the reporting cadence, and a gloss for the obscure finwire_ppk_avg_account metric. It does not mention data lag or the most recent month available, which would matter for a monthly bulletin series.

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 term expansion and source, then a single metrics list, with zero filler. It is one dense run-on sentence, and the parenthetical Polish gloss is heavy for the value it adds, but nothing is redundant.

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?

The tool is simple (one optional integer parameter) and has an output schema, so return-value explanation is not needed. Combined with annotations covering the safety profile, the description supplies the remaining essentials: source, cadence, and metric inventory.

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?

With only one optional parameter and 100% schema description coverage, the schema already carries the full semantics of 'history' (integer, 0-120, default 12). The description's phrase 'with monthly history' confirms the unit but adds nothing the schema does not already state, 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?

The description names the specific resource (PPK statistics from the PFR Portal monthly bulletin) and enumerates exactly which metrics are returned: net assets of target-date funds, active accounts, participation rate, average management fee, institutions, and finwire_ppk_avg_account. That level of detail lets an agent separate it from get_pension_stats or get_ike_ikze_stats without opening the schema, though it is a noun phrase rather than an explicit verb and never names the siblings it is not.

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 statement and no reference to the obvious alternatives in the sibling list (get_ike_ikze_stats, get_pension_stats, get_finwire_index). The agent must infer from domain knowledge that this is the PPK-specific source.

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