update_activity

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

Annotations establish this is a non-read-only, non-destructive mutation; the description adds crucial semantics annotations cannot convey: notes are replaced rather than appended, shoes overwrite the existing pair, and "none" removes shoes entirely. It also states the response reports prior values, which matters for a mutation tool.

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?

The core behavior and partial-update rule are front-loaded in one sentence, and the Args block gives one tight line per parameter. Slightly list-heavy but every line carries real information, with no repetition of the schema.

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 five-parameter mutation tool with an output schema already present, nothing essential is missing: overwrite vs append semantics, the removal sentinel, valid type values, and cross-tool references are all covered. Return-format explanation is rightly not duplicated.

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 does: it documents all five parameters, gives the source for activity_id and shoes, explains the string sentinel "none" for removal, and provides concrete activity_type values (trail_running, indoor_cycling, walking) that the schema's free-form string otherwise leaves open.

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?

Opens with a specific verb and resource ("Change a recorded run or ride") and enumerates the exact editable fields, so it is instantly distinguishable from read-only siblings like get_activity_details or get_activities. The scope (per-activity metadata edit) is unambiguous.

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?

Explicitly says to pass only changed fields (partial update) and routes the agent to get_activities for activity_id, get_shoes for shoe names, and get_activity_details for reading current notes. It stops short of stating when not to use it (e.g. for workouts, use update_workout), but the context is otherwise clear.

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