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

Goes well beyond the readOnly/idempotent/openWorld annotations by disclosing billing ('1 credit + 1 credit per user_result returned') and pagination mechanics. It does not cover rate limits, auth requirements, or error behavior beyond what the schema already states for cursors, so it is strong but not exhaustive.

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 purpose and use case, then cost and pagination — a sensible order. The final sentence about calling again with cursor partially restates both the opening pagination sentence and the schema's cursor description, which is mild redundancy.

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 names the return channel (meta.nextCursor) and the per-result billing model. It does not describe what fields a returned account carries, leaving a small gap, but an agent has enough to invoke and paginate correctly.

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 query, limit, and cursor are already fully documented. The description adds only the ranking semantics of the query and the fact that results are billed per account; it does not enrich individual parameter meanings beyond the schema baseline.

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 X accounts) plus a precise scope: name, username, or bio matching, ranked by X's people search. It also implicitly distinguishes itself from the lookup siblings by framing its job as converting a person/brand name into a username before calling 'the other account endpoints'.

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 a clear use case ('turn a person or brand name into a username before calling the other account endpoints'), which is strong routing guidance against get_x_user/get_x_users. It does not explicitly state when not to use it (e.g., for direct handle lookups), so it stops short of full exclusion guidance.

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