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 safety profile is covered. The description still adds real behavioral context beyond that: what the results contain ('titles, summaries and links to cite') and the empty-query default of returning the newest entries.

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?

Two sentences, verb-first, with zero filler. The topic enumeration is long but functional, since it doubles as retrieval vocabulary, and the operational hint about an empty query is placed last where it is easy to find.

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 two-parameter, read-only tool with no output schema, the description covers what it searches, what it returns (titles, summaries, links) and the zero-arg behavior. The only meaningful gap is the absence of a when-to-use statement relative to its three siblings.

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 only 50% (the `limit` parameter has no description), but the description compensates richly for `query` by specifying the topic space it searches and telling the agent that an empty query lists the newest items. The bounds and default of `limit` remain documented only in 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?

States a specific verb and resource ('Searches CertifiKit's plain-English guides on certificates of insurance') and enumerates the covered topics, which makes it clearly distinct from a checker like check_certificate or a builder like build_insurance_requirements. It stops short of naming any sibling as an alternative, so it doesn't fully earn 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?

The only explicit usage instruction is 'Leave query empty to list the newest,' which addresses one invocation mode. There is no guidance on when to consult guides versus calling check_certificate or build_insurance_requirements, nor any stated prerequisites, so the routing signal is only implied.

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