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

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=true, so safety is covered. The description adds value beyond that by disclosing the returned content (contact names and roles) in the absence of an output schema, and by noting the scope can be one client or all clients.

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 compact sentences: what the tool returns first, endpoint second. No filler, and the scoping nuance is front-loaded where an agent will read it.

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?

A read-only list tool with fully documented parameters and no output schema; the description supplies the missing return-shape information. Pagination behavior is covered by the schema, so nothing critical is missing, though a note on search semantics would round it out.

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 100%, so page, per_page, search, and client_id are all documented in the schema itself. The description only reinforces client_id filtering via '(or of all clients)' and says nothing about search or paging semantics, 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?

States a specific resource (client contacts) and the fields returned (names, roles), plus the backing endpoint 'GET /client-contacts'. It's unmistakable against the sibling list since no other sibling deals with contacts, but it never explicitly differentiates itself from invbg_get_client or invbg_list_clients, keeping 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?

The parenthetical '(or of all clients)' hints that omitting client_id returns everything, but there is no explicit when-to-use statement, no mention of the search parameter's role, and no guidance on when to prefer invbg_get_client over this tool. Usage is only implied.

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