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

Beyond the annotations (readOnly, idempotent, non-destructive, openWorld), the description discloses response shape ('compact rows (id, name, contact, status)'), result ordering ('best matches first'), a duplicate-flagging behavior, and API cost ('Mindbody calls: 1 (at most 1)'). These are non-obvious traits an agent could not infer from the structured fields.

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?

Four short sentences, front-loaded with what the tool does and what it returns, followed by sibling routing. No filler and no repetition of annotation content.

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?

There is no output schema, so the description must carry the return contract — and it does, listing the returned columns, sort order and duplicate flagging. Combined with the schema-documented parameters and the safety annotations, nothing needed to call the tool correctly is missing.

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%, so query, limit, siteId and includeInactive are already fully documented in the schema. The description restates the query modes (name/email/phone) but adds no format or precedence detail beyond what the schema provides; the 3 baseline applies when the schema carries this burden.

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?

The description opens with a specific verb and resource ('Find clients by name, email or phone') and immediately distinguishes the tool's scope from siblings by naming client_overview for detail lookups and clients_at_risk for a different search intent. An agent can select this tool without opening the schema.

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?

It gives explicit routing: use the returned id with client_overview for one client's details, and use clients_at_risk when looking for clients who may not renew rather than a known client. Both alternatives and the condition that selects them are stated outright.

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