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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=true), so the description's added value is the return-field list and the explicit statement that name/subject filters are EXACT matches — a meaningful caveat that prevents an agent from assuming substring search. It stops short of saying whether drafts, archived or deleted messages are included, which 'saved' leaves ambiguous.

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 tight sentences plus a short endpoint tag, with the resource and returned fields front-loaded before the filter options. Nothing is padded and no sentence is wasted.

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, listing the returned fields (id, type, name, subject, sender) is exactly the compensation needed, and pagination is carried by the schema. Minor residual gap: no statement about default ordering or whether inactive/deleted messages appear in results.

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 80%, so name, limit and offset are already documented in the schema (offset even explains next_offset paging). The description only adds the 'exact' qualifier for name/subject and the type filter, the latter being the only enum in the schema and left undescribed there. Baseline 3 is appropriate.

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: 'List saved email and SMS messages (templates and campaigns)' plus the fields returned and the filters available. The verb 'List' separates it from the sibling vision6_get_message or vision6_create_message, but the description never names those siblings to make the boundary explicit.

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?

'Filter by type or exact name/subject' implies when the filters apply, but there is no explicit when-to-use vs when-not guidance and no routing to alternatives such as vision6_get_message for a single record or vision6_list_folders for organising them. Usage is inferable from the name, not stated.

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