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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the burden is light. The description still adds real behavioral context: ordering (newest first), grouping (one thread per contact), the fields surfaced (unread counts, open/closed, last message), and the presence of an email-sending connection flag.

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?

A single dense paragraph that front-loads what is returned and follows with filtering and triggers. Every clause carries information, though the packing of five distinct facts into one paragraph slightly reduces scannability.

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 read-only, three-parameter listing tool with no output schema, the description usefully enumerates the returned data and the filtering/search surface, so an agent can call it correctly without guessing at 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 67%, and the description compensates for the undocumented 'query' parameter by specifying it searches 'name, email or text'. It also mirrors the view filter values, adding meaning beyond the bare enum. It does not explain the limit ceiling, which the schema already covers.

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 ('List the person's ShearQuery conversations') and sharpens the scope to 'one thread per contact, every email with them', newest first. That is enough to separate it from a single-conversation reader, but it never names or contrasts with the sibling crm_conversation, so it stops short of 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?

Gives concrete invocation triggers ('any new messages?' or 'who replied?') and explains the available narrowing (unread, open/closed, search by name/email/text). No explicit when-not-to-use or named alternative, so it is clear context without routing.

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