Get today's agenda

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

Annotations already declare readOnlyHint/idempotentHint, so the safety profile is covered; the description still adds real behavioral value by disclosing the aggregation window (next 24 hours for reminders, 'coming up' for dates), the conditional inclusion of calendar events ('when a calendar is connected'), and the fact that it takes no input. That is substantive context beyond structured fields.

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 what the tool does, then usage routing, then return shape — a sensible order with no filler. The return-format sentence is dense (section names plus a sample bullet template) but it earns its place given there is no output schema; slightly verbose for a no-parameter tool.

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?

There is no output schema, and the description compensates by describing the plain-text return: the date line, the exact section headers, and the '- #id title (due …)' bullet format. Combined with the usage routing and read-only disclosure, an agent has everything needed to call it and parse the result.

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?

With zero parameters the baseline is 4, and the description supports it by stating explicitly that the tool 'takes no input', removing any ambiguity about whether a date or filter could be passed. There is nothing further to document.

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 ('Get the owner's agenda for today in one view') and enumerates exactly what is aggregated: to-dos due/overdue, high-priority undated, reminders in 24h, calendar events, upcoming dates. It also explicitly distinguishes itself from list_tasks, so an agent can separate the two without opening schemas.

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 selection rule: 'Use it for "what's on today"; use list_tasks for the whole to-do list with filters.' It also names the downstream tools that consume the returned #ids (complete_task, update_task, delete_task), which tells the agent how this tool fits into a workflow rather than standing alone.

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