cite_event

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

Beyond the annotations (which already signal a safe, non-destructive write), it discloses that the citation is resolved-or-created and appended to the citation list, that duplicates are suppressed, and that no other event field is modified. This is useful mutation context. The only nuance is mild tension between "no duplicates" and idempotentHint=false, but it does not rise to a contradiction.

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 core action in the first sentence, followed by usage and then mutation behavior. Every sentence earns its place: scope, when-to-use examples, resolution behavior, and the no-side-effects guarantee, with no filler.

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 two-parameter mutation tool with a nested citation object and no output schema, the description covers purpose, usage, and side-effect behavior adequately. It is nearly complete; the only unaddressed element is what the call returns, which is a minor gap given the mutation nature of the tool.

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 both parameters and the nested CitationInput (including its precedence rules) are already fully documented in the schema. The description restates the resolution modes ("existing handle/id, or an inline source_title + page + confidence") without adding format or precedence detail beyond the schema, so the baseline of 3 is appropriate.

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 states a specific verb (attach) and resource (citation to an event) with a scoping qualifier ("that ALREADY exists"), which cleanly separates it from event-creation tools like add_event. It does not explicitly contrast against the obvious siblings cite_object (generic) or cite_child_link, so an agent must infer the tiebreak rather than being routed to the right sibling.

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?

"Use this to source an event you didn't create with an inline citation" gives clear when-to-use context, reinforced with concrete examples (Gramps web UI events, results from list_unsourced_facts). However, it names no alternative tool and states no exclusions, so the agent isn't told when to prefer cite_object or how to handle events it did create.

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