analyze_persona

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

Annotations only cover readOnlyHint and openWorldHint; the description carries the rest and does so richly: it enumerates the preset bundle contents (monthly volume, maker share, funding hours, clip size, withdrawal and fiat habits), the cost components summed, and the returned artifacts (cost-mix %, per-component cheapest leader, winner with reasons and trade-offs). It also discloses failure semantics elsewhere in the params (live request failures fall back to bundled baselines and are recorded in 'failures', shallow depth yields a warning).

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 content is dense and mostly earns its place, but the entire description is written twice, first in Chinese then in English, which roughly doubles length without adding information for a single reader. Front-loading is reasonable (the use case and persona list appear before the return description), but the duplication and multi-clause sentences hurt scannability.

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?

There is no output schema, so the description must describe the return, and it does: ranked venues, cost-mix percentages, per-component cheapest leader, an overall winner with reasons and trade-offs, plus tailored advice. Combined with 100% schema coverage for the 16 inputs, an agent has everything needed to call it and interpret the result.

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 the baseline is 3, and the enum values for persona are explained in the schema itself. The description adds one genuinely non-derived fact — that every preset parameter can be overridden (hence the 16 optional fields) and that persona id plus country code are required — which is the key mental model for using the schema. It does not add format or interaction detail for the remaining overrides.

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 states a specific verb+resource: it loads a named persona preset and 'runs the FULL annual cost stack across every venue allowed in the country', returning ranked venues with cost-mix and a winner. That is far more than a restatement of the name. It does not, however, explicitly differentiate itself from close siblings such as compare_personas, calculate_annual_cost, or recommend_exchange, which an agent would need to disambiguate.

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?

It gives concrete when-to-use triggers (user describes their trading style, asks which exchange fits them, or wants an all-in annual cost for a scenario), which is genuinely useful. But with 19 siblings including recommend_exchange, calculate_annual_cost, compare_total_cost and compare_personas, no alternative is ever named and no exclusion is stated, so routing remains inferential.

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