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

Annotations already declare readOnlyHint=true, openWorldHint=true and destructiveHint=false, so the safety profile is covered; the description adds the 50-id batch ceiling, the optional payload expansions, and the underlying GET endpoint. It stays silent on what happens with ids that don't exist (partial results vs. error), which is the main remaining behavioral unknown for a batch fetch.

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 is front-loaded in the opening clause, and the long semicolon-separated field list is dense but each clause carries real information about return content. Slightly over-packed for a single sentence, but no filler.

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?

With no output schema, the description carries the burden of describing returns and does so thoroughly via the field inventory and the two opt-in expansions. The gap is failure semantics for missing/invalid ids, which matters for a batch-by-id tool.

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 description coverage is 100% – all three parameters, their bounds (1-50 ids, maxItems 50) and both booleans are already documented in the schema. The description reinforces the id limit and names the payload each flag unlocks (custom field values, full postal addresses), but adds no syntax or format detail beyond that, 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?

Specific verb+resource: 'Full records of one or more contacts by id', followed by an explicit inventory of returned fields and a batch cap of 50. The 'by id' scoping implicitly separates it from brightpearl_search_contacts, but that sibling is never named, so the differentiation 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 'by id' framing and 'Up to 50 ids' hint that this is a batch retrieval for already-known ids, implying search_contacts is the right tool when ids are unknown. However, no explicit when-to-use/when-not guidance or alternative is stated.

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