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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), and the description adds real context beyond them: the data is limited to the latest completed sync (freshness), results are capped at 20 (completeness limit), and email, postal addresses and Xero IDs are stripped (a return-shape constraint). It does not say what happens on an empty or not-yet-synced case, but the added disclosure is substantial.

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 with no filler, and the most important constraint (which sync the data comes from) is front-loaded before the result limitations. Every clause carries information an agent needs.

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?

An output schema exists, so return values need no explanation, and the description still flags which fields are omitted. It also states the sync scope and cap. The only real omission is match semantics for query and behavior when no completed sync exists, which are minor for a read-only search.

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 33%, with just workspace_id documented, so the description must compensate for query and limit. It does partially: 'by name' explains query's meaning and 'capped at 20' explains the limit ceiling, but it never says whether the name match is exact or partial, nor what the default limit is. The workspace_id guidance lives entirely 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 ('Search customer contacts') plus a precise data scope ('signed-in owner's latest completed SHVL Xero sync') and the matching key ('by name'). It is clearly distinguishable from get_xero_contact and search_xero_invoices in practice, though it never names a 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?

The 'by name' phrasing and the mention of only one sync imply this is a lookup-by-name entry point, but there is no explicit when-to-use or when-not guidance and no pointer telling the agent to fall back to get_xero_contact for full record detail. Usage is inferable rather than stated.

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