departi_check_visa

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

The annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is clearly read-only. The description adds value by confirming the data source ('sourced from official immigration authorities') and by specifying that the tool returns details like cost and processing time, which goes beyond the schema. However, it does not elaborate on rate limits, caching, or what happens if the data is unavailable (e.g., unsupported passports). With good annotations, a 3 is appropriate.

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 description is a dense single paragraph that front-loads the core purpose and then provides structured output details, usage phrases, sibling references, and a practical tip. Every sentence adds value, and there is no repetition or fluff. It could be slightly more terse (e.g., reducing the exhaustive list of output fields), but overall it is well-organized and efficient.

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?

Given that there is no output schema, the description does a good job of listing what fields are returned (visa/permit type, requirement, max stay, work allowance, cost, processing time, notes). The three required parameters (nationality, destination, duration) are clearly explained, and optional parameters (purpose, locale, currency) are also covered. The only gap is that there is no mention of error handling, rate limits, or data freshness, but for a read-only lookup tool with strong annotations, this is sufficient.

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 schema already documents each parameter and its format (ISO alpha-2, integer > 0, etc.). The description adds significant extra context: it clarifies that nationality should be the traveller's passport country (not tax residence), it gives examples ("PT", "BE"), it explains that multi-nationals may benefit from choosing the best passport, and it lists the valid purposes (tourism, remote_work, etc.). These additions justify a 4 rather than a baseline 3.

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 starts with a specific verb ('Returns') and a clear resource ('entry/visa options'), and goes on to specify the exact inputs (nationality, destination, purpose, length of stay) and the full set of outputs (visa type, requirement, max stay, work allowance, cost, processing time, etc.). It also explicitly distinguishes this tool from sibling tools like departi_track_schengen and departi_check_tax, which helps an AI agent know exactly when to use this one.

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?

The description explicitly states when to use this tool ('what visa do I need / can I stay N days / can I work remotely here') and directly names two alternatives with their distinct use cases: departi_track_schengen for counting days against the 90/180 limit, departi_check_tax for tax consequences. It also gives a practical tip about handling multi-nationals, which further guides selection. This is exceptional guidance.

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