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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description still adds genuine behavior: the 20/100 result cap, cross-salon scope, unordered results, and no name-search capability — none of which appear in 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?

Three dense sentences ordered by importance: trigger, return shape/caps, then exclusions. Every clause carries usable information and nothing is redundant filler.

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 an output schema present, return-value explanation is optional, yet the description still summarizes the payload, defaults, and scope. Combined with the annotations covering safety, an agent has everything needed to call this correctly.

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 both parameters (limit, salonId) are already documented, including the 20 default / 100 max and the salon scoping semantics. The description restates these without adding format or edge-case detail beyond the schema, so the baseline 3 applies.

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 names a specific verb and resource ('who their clients are'), states the scope (all salons or one), the fields returned (id, name, salon, last edit time), and the cap (100 max, 20 default). It also implicitly distinguishes itself from get_client by noting it returns a list without a name search, so an agent can route correctly 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 an explicit trigger ('when someone asks who their clients are, or needs a client id to look up that person's appointments, payments or quotes') and an explicit exclusion ('Not for a client's email, phone or notes'). It also flags the absence of name search, steering the agent elsewhere for that case.

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