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

Adds real behavior beyond readOnly/non-destructive annotations: it discloses that resident numbers are never returned, that row_index/row_key are emitted per subscriber, and that each call consumes one token. The multi-sentence idempotency-key paragraph is generic boilerplate awkwardly grafted onto a read-only search, which dilutes rather than clarifies.

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?

The purpose and precondition are front-loaded, but four sentences of idempotency-key policy plus a Korean token-cost note bloat a simple two-parameter search, and the retry paragraph is only tangentially relevant to a read-only operation.

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?

With no output schema, the description usefully characterizes the return (row_index/row_key per subscriber, no resident numbers) and gives the auth precondition, which is enough for an agent to plan a call. Pagination defaults are left to the schema, which is acceptable.

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 100%, so the baseline is 3; the description earns an extra point by tying account_link_id to the login session ('same account_link_id') and by explaining what search_text produces is fed into. The request_idempotency_key guidance is mostly a pointer back to the description's own boilerplate.

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 and resource ('Search workplace subscribers eligible for the NPS membership certificate (EC02)') plus the search key (by name), which clearly separates it from nps_edi__b1__certificates__membership__issue and __apply.

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 an explicit precondition (prior nps_edi__auth__npki_session__login with the same account_link_id) and names the downstream consumer of its output (the issue tool). It does not contrast against nearby alternatives such as workplace_subscribers__status or application_results__search, so it stops short of a 5.

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