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

readOnlyHint=true already declares this is a safe read, and the schema documents the past-services and pagination behavior. The description reinforces the 'upcoming by default' default and hints that field expansion increases payload scope, but adds nothing on auth, rate limits, or result shape. Some added context, not rich.

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 short sentences, front-loaded with the core behavior and default scope, with the field-expansion guidance second. The trailing 'Elvanto: services/getAll' is a minor API mapping note that earns its place but is not description-critical.

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 read-only list tool with 8 optional parameters and full schema documentation, the description covers default scope, field expansion, and intent. Pagination and return shape are handled by the schema and the absence of an output schema, so nothing essential 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%, so every parameter including the fields enum values (volunteers = roster, plans = order of service, songs) is already documented in the schema. The description's restatement is helpful framing but adds no syntax or format detail beyond it; 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?

States a specific verb and resource ('List services') plus the default scope ('upcoming by default'), which is real information an agent needs. It does not name or contrast with the obvious sibling elvanto_get_service, so it stops short of full sibling differentiation.

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 concrete usage framing: add volunteers/plans/songs 'to answer "who is serving Sunday?" or "what are we singing?"', which tells the agent when to expand fields. It offers no when-not guidance, such as when to call elvanto_get_service for a single service instead.

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