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

Annotations already declare readOnlyHint=true, openWorldHint=false and destructiveHint=false, so safety is covered. The description adds genuinely useful behavior beyond that: omitting workspace_id fans out across ALL of the user's workspaces with per-item attribution, and the default day is the user's timezone, not UTC, with a concrete Buenos Aires/21hs example. It stops short of describing return shape or item ordering, so a 4 rather than 5.

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-loads the core purpose in the first sentence, then layers scoping constraints and the timezone caveat in descending order of importance. Every sentence carries a distinct instruction; none is 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 zero-required-parameter read tool with no output schema, the description covers everything an agent needs: what is aggregated, workspace scoping, multi-day usage, and the timezone default. No output schema exists, so return-value explanation is not required.

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 coverage is 100%, so the baseline is 3, but the description adds real semantic value: it explains that workspace_id omission means an all-workspace fan-out, that date+hasta together express a multi-day window (with the Monday-to-Sunday week pattern), and that date defaults to today in the user's timezone. This is more than restating the schema.

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+resource (retrieve the day's/multi-day agenda) and enumerates exactly what it aggregates: calendar events, due tasks, still-open overdue tasks, and upcoming reminders. It explicitly distinguishes itself from the siblings get_events and get_tasks by naming them as the manual alternative it replaces.

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 explicit when-to-use ('¿qué tengo hoy/mañana/esta semana?') and multiple when-NOT-to-use rules: don't call once per workspace, don't call one day at a time, and don't bolt on get_events or get_tasks for the same data. The alternative and the condition selecting it are both named.

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