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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds genuinely useful context beyond that: client notes are staff-only, pet records exist in DaySmart Pet only, and the call requires a Cotlet API key with access to this app. These are real operational caveats an agent could not derive from the annotations.

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?

The second sentence largely restates the first ('client profile, client notes, balance, upcoming appointments, pets'), which is redundant. The genuinely additive facts — staff-only notes, DaySmart Pet scope, API key requirement — are appended at the end rather than front-loaded, so the structure is serviceable but not tight.

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 properly takes on the burden of describing what comes back, down to the four pet comment categories. Combined with the platform and auth caveats, an agent has enough to invoke it correctly; the only meaningful omission is guidance on when to prefer this over the search sibling.

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?

There is a single parameter with 100% schema description coverage ('Client ID from find_clients'), so the schema already does the work. The description adds nothing about the identifier beyond implying a full profile lookup. Baseline 3 is correct when the schema carries the meaning.

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?

Names a specific verb (get) and resource (client profile) and enumerates the payload: contact details, notes, balance, upcoming appointments, and pets with per-category comments. An agent instantly knows this is a single-client detail fetch. It does not, however, contrast itself with the sibling daysmart_find_clients, 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?

There is no when-to-use or when-not-to-use guidance. The natural alternative, daysmart_find_clients (referenced only inside the schema's client_id description), is never mentioned in the description, so routing between 'search clients' and 'fetch one client' is left entirely to inference.

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