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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered by structured data. The description adds only 'Returns the events with times and links', which duplicate what the existing output schema already conveys, and says nothing about ordering, paging, or the idempotentHint=false implication.

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?

Two sentences, zero filler, with the usage trigger front-loaded and the sibling routing placed last where it matters. Every clause earns 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 single optional-parameter, read-only list tool, the description supplies the trigger, the scope of results, and the disambiguation to the alternative; return values are already covered by the output schema and safety by annotations. Nothing an agent needs to invoke it correctly is missing.

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% and the single parameter is fully documented in the schema ('today | week | month | a YYYY-MM-DD date; default upcoming'). The description's list of ranges restates the same options without adding format or default semantics beyond the schema, so the 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 (list calendar events) plus the accepted range scope, and explicitly names the sibling it is not ('For a combined view ... use my_agenda'). An agent can distinguish it from my_agenda, reschedule_event and add_event without opening any schema.

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 an explicit trigger ('Use this when the user asks what is on their Xenition calendar for a range — today, this week, a date, or upcoming') and routes the combined-view case to the named alternative my_agenda. Both when-to-use and when-not-to-use are stated.

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