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 the auth requirement ('Needs the user's Cotlet API key with access to this app'), which is genuinely useful, but it also states 'Returns every location' immediately followed by 'Multi-location businesses read one location per call,' an ambiguous/contradictory claim about call cardinality that muddies rather than clarifies behavior.

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?

Front-loaded with the resource and its fields, and every sentence carries information. The redundant 'Vagaro:' vendor prefix and the choppy one-location sentence are minor wastes.

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 parameters and no output schema, the description does the necessary work: it names the returned fields, the auth prerequisite, and how to use the returned location_id. The only gap is the unresolved one-location-vs-all ambiguity.

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 are zero parameters and the schema is empty, so this dimension is essentially neutral. Baseline of 4 applies; the description correctly adds nothing about parameters because none exist.

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 and resource ('Returns every location of your Vagaro business') and enumerates the fields returned (address, time zone, phone). An agent can immediately tell this apart from the appointment/service/list siblings in the Vagaro family.

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?

Gives an explicit downstream usage rule ('Use location_id from each item in the other calls'), which tells the agent why to call this and how to consume the result. It does not need to name an alternative since no sibling lists locations, but it offers no when-not guidance.

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