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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is covered by structured data. The description adds genuine value by enumerating the returned fields (name, salon, language, last edit time), which is behavioral context beyond what annotations express. Output schema exists, so full return-value narration isn't required, but the field list is a useful addition.

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 short sentences, zero waste, front-loaded with the trigger condition followed by return-value summary and exclusion. Every sentence earns its place.

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?

Given a single well-documented parameter, full annotation coverage, and an output schema, the description covers when-to-use, when-not, and what's returned. It could be slightly stronger by naming the specific alternative for the excluded cases (email/phone/booking history), but otherwise nothing an agent needs 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% – the clientId parameter is fully documented in the schema with format and source guidance. The description adds nothing about the parameter, which is acceptable given the baseline-3 rule when schema coverage is high.

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+resource (get one salon client) and distinguishes from siblings by naming list_clients implicitly and contrast with other get_* tools via the 'one salon client' framing. Explicitly scopes to a single client, unlike the list_* siblings.

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?

Provides a clear when-to-use trigger ('when someone asks about one salon client') and an explicit when-NOT ('Not for the client's email, phone or booking history'), routing the agent away from inappropriate alternatives. The negative guidance is unusually specific for this category.

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