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

Beyond the annotations (destructiveHint=true, idempotentHint=true), the description discloses the return payload (id, name, salon, changed fields) and a privacy rule that contact details are never returned. The main remaining gap is that it never states that omitted fields are left unchanged, which matters for a tool flagged destructive.

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 sentences, front-loaded with the trigger condition, followed by outcome and exclusion. Every clause carries information; there is no filler or restatement of the title.

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 six-parameter destructive update with an output schema, the description covers the trigger, the exclusion, the concurrency caveat indirectly, and the return shape. It falls short only on partial-update semantics and permission requirements, which an agent might still need to call it safely.

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 100%, so all six parameters including clientId and expectedLastEditTime are already documented in the schema, and the description's field list merely mirrors those properties. It adds no syntax, format, or constraint detail beyond what structured fields provide, so the baseline of 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 ('change a client's name, phone, email or language') and enumerates the mutable fields, so the agent knows exactly what the tool does. It also explicitly differentiates from the sibling create_client with 'Not for adding a new client.'

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 ('Use this when someone asks to change...') and an explicit exclusion ('Not for adding a new client'), which routes the agent to create_client for new records. No inference is required to pick between the two.

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