My Day Tool

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

Annotations already declare this a read-only tool, so the safety profile is covered. The description does add real behavioral context beyond that: today's result includes in-progress tasks and focus, while past days do not, and viewing a colleague requires permission you may not have. It still says nothing about result limits, aggregation granularity, or what happens when the requested day has no data — modest added value given annotations carry the rest.

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?

Compact, front-loaded with the payload description, then defaults, then the trigger phrase, then the alternative. The middle sentence packs three ideas with semicolons and is denser than ideal, but every clause carries information and nothing is repeated.

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?

With no output schema, the description carries the burden of describing return values and it does so by enumerating the fields returned, including the today-only extras. For a read-only, two-optional-parameter tool this is nearly sufficient; only edge cases (empty days, aggregation rules) are unaddressed.

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% and already documents both params with formats, so baseline is 3. The description adds semantics the schema does not: both are optional with stated defaults, and 'person' is constrained to colleagues whose hours you are permitted to see — a meaningful eligibility constraint beyond 'part of the name or email'.

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 names the resource precisely and enumerates what a 'day' contains: minutes worked, per-hour (0-23) and per-project breakdowns, tasks done, plus in-progress tasks and focus for today. It also distinguishes itself from the sibling that reports the day (last_update). The opening is a noun phrase ('One person's day') rather than a verb, which slightly blurs whether this is a query or a report, but the payload is unmistakable.

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 states defaults (today, yourself), how to reach other data (date for an earlier day, person for a colleague whose hours you may see), gives the natural-language trigger ('what did I do today / on Tuesday?'), and explicitly routes an adjacent need to last_update. Nothing is left to inference about when to pick this tool.

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