set_activity_description

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

With no annotations, the description carries the transparency burden. It discloses key behavior: the field is overwritten/updated and an empty string clears it. It omits whether there are ownership/permission restrictions, any side effects on related data, or validation limits; those are reasonable gaps but notable because annotations are absent.

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 description is front-loaded with the core operation, then adds a short usage note and a compact Args section. Every sentence earns its place; there is no redundancy or boilerplate.

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 simple two-parameter setter with an output schema, the description covers parameter meanings, the purpose of the notes field, and the clear-edge case. It is slightly incomplete only in not addressing permissions or behavior when the activity doesn't exist, which would help given the absence of annotations.

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?

Although the input schema has 0% description coverage, the tool description includes an Args section explaining both parameters: activity_id is the target activity and description is the new text with clear semantics for empty string. This fully compensates for the bare schema properties.

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 opening sentence names a specific verb ('Set or update'), a specific resource ('activity'), and the target field ('free-text description (notes)'). This clearly distinguishes it from sibling set_* tools like set_activity_name and set_activity_type.

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 a clear usage context ('useful for recording how a session felt, kit used, conditions, niggles') and the clearing behavior, so an agent can decide when this tool fits. It does not explicitly name alternatives or state when not to use it, but the free-text-purpose framing makes the decision clear.

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