departi_track_schengen

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

Annotations already set readOnlyHint=true, idempotentHint=true, destructiveHint=false. The description adds substantial behavioral detail: return fields (days used, days remaining, status with four enumerated levels, projected date), the special handling for residence/digital-nomad permits (excludes issuing country days but counts all others), and the note that EU/EEA nationals are not counted. No contradictions with annotations.

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 single paragraph that front-loads the core function and outputs. Every sentence serves a purpose: initial summary, what it returns, target usage, and critical edge cases. No wasted words or repetition of schema details.

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?

Despite lacking an output schema, the description sufficiently explains the return structure (days used, days remaining, status, projected date). It also covers the residence permit and nationality exceptions. However, it does not mention error cases (invalid input, missing countries) or the exact format of the returned data (e.g., JSON object), leaving minor gaps for a tool with nested objects and no output schema.

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 baseline is 3. The description adds value by explaining the semantic logic of the residencePermit parameter ('When present and active... days in the issuing country are excluded') and clarifies that 'nationality' determines exemption. This extra context elevates the score above 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?

The description opens with a specific verb+resource: 'Calculates Schengen 90/180 short-stay status from a list of stays.' It also lists the exact outputs and the target audience (non-EU travellers). The sibling tools (visa, tax, accommodation, etc.) are clearly distinct, so this tool is uniquely positioned.

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 'Use for non-EU travellers tracking the 90-days-in-180 limit' and clarifies that EU/EEA nationals are exempt and residence permits only exempt the issuing country. It does not explicitly name when NOT to use (e.g., use departi_check_visa for visa status), but the sibling context combined with this directive provides sufficient guidance.

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