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

Annotations already declare readOnlyHint=true, openWorldHint=true and destructiveHint=false, so the safety profile is covered for free. The description adds genuinely non-structured context: the authentication requirement ('Needs the user's Cotlet API key with access to this app') and the fields the records carry (category, duration, price). It stops short of pagination/ordering behavior, but the added auth and payload context goes beyond what the annotations provide.

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 description spends two of four sentences restating the same idea ('Services with category, duration and price...' and 'Returns the services set up in your DaySmart account'), which is redundant. The useful content — the service_id/book_appointment link and the API-key note — is buried after the restatement rather than front-loaded.

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 simple, no-required-arg list tool with annotations covering safety and no output schema, the description supplies the essentials: what is returned, roughly which fields, the auth requirement, and how the result feeds book_appointment. Nothing critical is missing, though paging/ordering on larger catalogs is left unaddressed.

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% and there is a single optional 'category' filter already documented in the schema ('Only this service category.'). The description's mention of 'category' merely echoes the schema and adds no syntax, matching, or default-value detail, so the baseline of 3 is appropriate.

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 states a clear resource ('services with category, duration and price... as set up in your account') and what is returned ('the services set up in your DaySmart account'). It is unmistakably a list-services read, well-separated from the daysmart mutation siblings (book_appointment, void_appointment, update_appointment). The first sentence is a fragmentary noun phrase rather than a clean verb+resource statement, which keeps it just short of ideal.

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 one concrete downstream hint — 'Use service_id with book_appointment' — which implies this tool is the lookup step before booking. However there is no explicit when-to-use vs alternatives or when-not guidance, and no prerequisites for filtering. Usage is implied rather than stated.

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