List the good days

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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, destructiveHint=false), so the description only needs to add behavior beyond them. It does: result ordering ('oldest first'), the inclusion of a count per day, and the default no-filter behavior that returns the full history. It does not discuss limits or volume, but the added ordering and default-scope facts are genuinely useful.

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 compact sentences, with the core purpose and ordering front-loaded and the filtering behavior second. No filler, no restatement of the title, and every clause adds information.

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?

An output schema exists, so return-value documentation is not required, and the annotations cover the safety profile. What remains slightly thin is the meaning of 'with their count' (count of what) and any volume/limit expectation for the unfiltered case, but for a simple read-only list tool the definition is nearly complete.

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 both parameters are documented there, including the date format and the get_today cross-reference, so the schema carries the load. The description restates the filter semantics ('keep only a period; without them, every good day there is') without adding format, boundary inclusivity, or ordering-of-arguments detail beyond the schema. 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?

Names a specific verb and resource ('List the days ... good days'), explains the domain-specific source of the classification ('the app's summary marks as good days (Fitatu's own rule decides which)'), and states the ordering. This distinguishes it from siblings like get_day, get_range_summary and get_progress without needing to open 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?

It gives clear guidance on the date parameters ('Pass from_date and/or to_date to keep only a period; without them, every good day there is'), which is effectively a usage rule for the optional filter. However it never states when to pick this tool over get_day, get_range_summary or get_progress, so the alternative selection is left implicit.

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