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

Annotations already declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false, so safety is covered. The description adds behavioral value by disclosing the exact endpoint and that the response includes all line items, which tells the agent this is a detail-heavy read rather than a lightweight lookup.

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 is two compact sentences with zero filler. It front-loads the core behavior (one event plus line items) before appending the endpoint reference.

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 output schema, the description compensates well by listing the returned line-item fields and metadata. It is nearly complete for a simple single-id getter, though it leaves open details like pagination or absent-event behavior that an agent might wonder about.

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 is a single required event_id parameter with 100% schema description coverage, and the schema note even says it comes from parsley_list_events. The description itself adds no meaning beyond the schema, so the baseline of 3 is appropriate when structured fields carry the parameter story.

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 uses a specific verb-resource pair ("One event") and details the returned payload (metadata and all line items with item, amount, unit, station, section), plus the backing endpoint GET /events/{id}. It distinguishes itself implicitly from the list endpoint by emphasizing a single event, though it does not name parsley_list_events as the sibling alternative.

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?

Usage is only implied: retrieving a single event by id. The description gives no explicit guidance on when to choose this tool over parsley_list_events or the other sibling getters, and it does not state prerequisites or exclusions.

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