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

Annotations already declare readOnlyHint and openWorldHint=false, so safety is covered; the description adds real context: results are volunteered human contact cards with principles, boundaries and etiquette, and ordering is by crowd-sourced trust rather than relevance or recency. It does not discuss result size limits or paging behavior beyond the schema's offset/limit.

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?

Three tight sentences: what it finds, what comes back, how it is ordered. No filler, and the core purpose is front-loaded.

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 read-only, five-parameter search with no output schema, the description covers purpose, filter axes, returned fields, and ordering. Remaining gaps are minor: paging behavior, empty-result behavior, and whether filtering by topic requires a slug from list_topics (that hint lives only in the 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 coverage is 60%, so the schema documents query, topic, and ethics_consultants_only reasonably well. The description adds that free text and topic are combinable filters and that ordering is trust-based (implying no sort parameter), but says nothing about the ethics_consultants_only flag, limit/offset semantics, or what 'all words must match' means in practice.

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?

Names a specific verb and resource ('Find humans who have volunteered to be contacted by AI agents') plus the filtering axes (free text and/or topic) and the shape of the results. It implicitly separates itself from get_card (single card retrieval) by framing results plural, but never names a sibling to sharpen the boundary.

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?

'By free text and/or topic' implies how to drive the tool and that filters can be combined, and the audience constraint (only humans who volunteered) is stated. There is no explicit when-not guidance, no mention of preferring get_card once you have an identifier, and no advice on query vs topic selection.

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