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

Annotations only indicate readOnlyHint=false and destructiveHint=false; the description adds that this is a WRITE operation, requires specific coordinator roles, and that user confirmation is needed. This is useful behavioral guidance beyond the structured fields, although it could mention side effects or reversibility.

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?

Three short clauses deliver purpose, access control, and confirmation guidance with no wasted words. The key verb and resource are front-loaded in the first phrase.

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?

The role restriction and confirmation instruction cover important operational context, and an output schema exists. However, for a 10-parameter update operation with only 10% schema coverage, the description would benefit from stating that event_id plus optional fields can be supplied, and from noting the partial-update contract.

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 only 10% and the description provides no parameter-level guidance. It never explains that event_id is the required key, which other fields can be updated, or any format/constraints beyond the schema's bare property names.

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 opens with a specific verb and resource: 'Updates an existing school event.' This clearly distinguishes it from sibling creation tools like create_event and cancellation tools like cancel_event, so there is no ambiguity about what the operation 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?

It sets clear context: this is an admin-only mutation for existing events and tells the agent to confirm changes with the user. It does not explicitly name alternatives or state when not to use it, but the 'existing' qualifier and sibling names make the usage boundary reasonably clear.

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