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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint=false and destructiveHint=false, so the closing 'Read-only... stores nothing, sends nothing, calls no external services' sentence mostly restates structured data. It adds modest value by disclosing pagination fields (total, offset, limit, nextOffset) and that budget filtering silently excludes programmes with unknown amounts, but an output schema is present so the field enumeration is largely redundant.

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?

Purpose and scope are front-loaded, which is good, but it is a single dense paragraph and the tail enumerates return fields that the output schema already defines. Trimming that clause would sharpen the definition without losing information.

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 nine optional parameters, full schema coverage, an output schema and rich annotations, the description supplies the one thing structured fields cannot: corpus scale and coverage, plus the set of filterable dimensions. It is essentially complete for correct invocation; only explicit routing against the comparison and detail siblings is missing.

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 all nine parameters including enum meanings, defaults and the ISO/name country formats are already documented in the schema. The description only restates the filter categories at a high level and adds no syntax or edge-case detail (e.g. filter combination behavior) beyond the schema, so the baseline 3 applies.

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?

A specific verb-plus-resource statement: it searches the GoodbyeMatrix programme index, with concrete scope (170+ residency programmes, 80+ countries, 20 CBI programmes) and the enumerated filter dimensions. It never names a sibling tool (compare_programs, list_cbi_programs, get_program), so the agent must infer the boundary rather than read it, which keeps it below a 5.

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?

Usage is clearly framed: this is the paginated filtered-search entry point, and the filter list (country, region, type, budget, citizenship path, dual citizenship) tells the agent when this tool fits. There are no explicit exclusions or pointers to alternatives such as compare_programs for side-by-side comparison or get_program for a single record, so it stops short of 5.

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