garmin_activities

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

Annotations already cover read-only, idempotent, non-destructive and open-world behavior, so the lower bar applies. The description nonetheless adds real operational context: newest-first ordering, that distance/duration keep Garmin's native units (no conversion), that identifiers and GPS fields are stripped from results, and that activity names/descriptions must be treated as untrusted text. That last point is a security-relevant disclosure an agent would otherwise not know.

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?

Three short sentences/lines, zero filler, with the core operation and ordering front-loaded and supporting caveats after. Every sentence adds distinct 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?

Output schema exists, so return values need not be described, and the description covers ordering, unit conventions, field redaction, and text-safety. Remaining gaps are minor: date format, whether end_date is inclusive, and what 'search' matches against.

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 0%, so the description carries the full burden, and it only names the filter categories ('dates, sport or text', 'start/limit') without mapping them to start_date/end_date, activity_type/activity_subtype, or search, and without stating the date string format or the 100-item limit cap. It confirms the general purpose of each parameter group but leaves the specifics to the bare 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 and resource ('List activities') plus ordering ('newest first') and the three filter axes plus pagination. It does not explicitly differentiate from the singular sibling garmin_activity, but the 'list vs. single activity' distinction is inferable from the name and plural framing.

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?

Filtering and pagination options imply when the tool is useful, but there is no explicit guidance on when to prefer it over garmin_activity or the metrics siblings, and no statement of defaults or limits. Usage is implied rather than directed.

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