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

With no annotations, the description carries the full burden of behavioral disclosure. It clearly signals a read-only fetch and clarifies that the id parameter accepts either an id or slug, which is valuable. However, it does not mention behavior when the event is not found, whether fetching has any side effects (especially relevant given the mark_seen sibling), or what the response contains.

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 entire description is a single, front-loaded sentence with no filler. Every word earns its place, and the key information (operation, resource, and parameter interpretation) is delivered immediately.

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-parameter fetch, the description is adequate, but it leaves gaps: it does not describe the return value (no output schema is present), how to handle missing events, or how this relates to the sibling tools. The id-or-slug nuance is the only added context beyond the schema, and an agent might still wonder whether search_capabilities should be used first.

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 0%, so the description must compensate. It adds meaning to the lone id parameter by stating it can be either an id or a slug, which is not evident from the plain string type in the schema. It could be even richer with examples or format constraints, but it gives the agent the essential disambiguation.

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 (Fetch), a precise resource (a single capability event), and a clear access method (by id or slug). It is immediately distinguishable from siblings such as list_recent_capabilities, search_capabilities, and mark_seen, which cover listing, searching, and mutating.

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 implies the trigger condition: use this tool when you already have an id or slug for a specific capability event. It does not explicitly contrast with the sibling tools or state when not to use it, but the single-resource focus provides clear enough context for an agent to select it appropriately.

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