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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so safety is covered. The description adds a genuinely useful return contract – that results include each tool's input for use_tool – plus the no-query full-listing behavior, which the annotations cannot convey. It stops short of describing result size, ranking, or behavior when no tool matches the query.

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 the use_tool handoff are front-loaded, which is right, but the middle enumeration ("quiz nights, club schedules, comments, jobs, efterlysningar...") is long, includes an untranslated word and a vague "their collaboration model and more", diluting the signal. It is adequately sized but not tight.

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?

For a one-parameter discovery tool with annotations and no output schema, the description covers what it does, how to query it, what the response contains, and the zero-query case – enough for an agent to call it correctly. The only real gap is the empty-result path, which is minor at this complexity.

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?

The single query parameter has 100% schema coverage and an example in the schema ("club schedule", "friend code", "read_comments"), which sets the baseline at 3. The description adds that English keywords or an exact tool name are both accepted and that omitting the query returns everything, but it gives no guidance on matching precision or multi-word behavior – marginal value over the schema.

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?

"Find a Hunchful tool that isn't in your list" gives a specific verb (find) and resource (tool), and the closing clause says the result is each tool's input, runnable via use_tool – which separates it from the use_tool sibling. It is not tautological like the title alone, though the phrase "your list" is never defined, so the discovery scope is inferred rather than stated.

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 implies the trigger condition (you need a capability that isn't already exposed) and explicitly handles the degenerate case with "No query: everything there is." It never names a competing tool such as search or find_people, nor states when-not to use it, so there is no full when/when-not/exclusion triad.

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