List contacts

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds the meaningful behavior that an unfiltered call returns the entire contact set, but says nothing about result volume, pagination defaults, or ordering — relevant for a potentially large list.

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 short sentences, front-loaded with the core action, with the unfiltered-case behavior placed second where it belongs. No filler or redundant restatement of the title.

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 6-parameter, zero-required read tool with no output schema, the definition covers the filters and the no-filter case but omits pagination behavior and any indication of what a result entry looks like. It is adequate to invoke correctly, but leaves the agent guessing about result size and paging.

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 67%, and the description merely enumerates the four filter fields (name, IČO, DIČ, email) that the schema already documents, including the partial-match semantics for name and email. The two pagination parameters (page, pageSize) are undocumented in both places, so the description does not compensate for the coverage gap.

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 ('Search contacts') and even disambiguates the domain term with 'kontakty: customers and suppliers', plus names the four searchable fields. It is clearly distinct from the single-record get_contact sibling by being a search/list operation, though it never names that sibling explicitly.

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?

'Without filters, lists all contacts' gives one useful usage branch (filtered search vs. full listing), so the agent knows the tool is safe to call with zero arguments. However, there is no guidance on when to prefer get_contact for a single record, nor any note on when to combine filters.

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