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

Goes well beyond the annotations: it spells out the consequence of non-idempotency ('a repeated call creates a second event'), describes the return payload ('the new event and an undo_id'), names the recovery tool and its time limit ('teamup_undo_event_action removes the event again within one hour'), and cites the endpoint. The duplicate-creation and undo-window facts are exactly what an agent would otherwise get wrong.

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?

Five short sentences, all front-loaded with the operation type and requirements. Nothing is redundant; each clause either sets a precondition, a required input, a behavioral caveat, or a recovery path.

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 15-parameter mutation with no output schema, the description supplies the missing pieces: permission requirement, minimum inputs, non-idempotent consequence, the contents of the reply, and a one-hour undo route. An agent has everything needed to call it safely.

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 93%, so the schema already documents nearly all 15 parameters including formats and defaults. The description only reiterates the three required fields, adding no syntax or constraint detail beyond the schema. 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 up front ('WRITE: create an event') and lists the three minimum required fields, so the agent knows exactly what the call produces. It does not explicitly name a sibling (e.g. teamup_update_event) to contrast against, but the create-vs-mutate distinction is unambiguous from the verb.

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 the concrete precondition ('Needs a calendar key with add or modify permission') and the minimum input set ('at least subcalendar_ids, start and end'), which is clear usage context. It stops short of stating when-not to use it or naming teamup_update_event as the alternative for changing existing events.

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