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

The annotations already declare read-only, idempotent, and non-destructive behavior. The description adds no extra behavioral detail such as error cases, return format, or side effects, so it provides only baseline transparency beyond the annotations.

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 short but contains significant redundancy: 'Retrieve one CMS agenda event by event id after cms_list_events discovery when needed.' is repeated verbatim as 'Guidance:', followed by an unclear '| context: id' fragment. The repeated sentence does not earn 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?

For a simple single-event retrieval tool, the description provides sufficient context: it identifies the resource, the required id, and the recommended discovery flow. It does not mention output shape or error behavior, but the absence of an output schema makes this acceptable for such a straightforward read operation.

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?

The parameter schema is fully covered by the description in the schema itself, but the description adds helpful context by specifying that the id is returned by cms_list_events. This gives the agent a clear source for the parameter value.

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 clearly states the action (retrieve), the resource (one CMS agenda event), and the key identifier (event id). It is immediately obvious what the tool does.

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?

The description gives practical guidance to use this tool after cms_list_events discovery and only when needed. It does not explicitly contrast with sibling tools like cms_get_event_paragraph, but the resource type is clear enough to avoid confusion.

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