update_activity

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It adds valuable context beyond the schema by specifying partial-update semantics and the return type (JSON string with updated activity information). It does not mention side effects or error cases, but the core behavior is well-covered.

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 well-structured with a clear summary, behavior note, Args list, and Returns. It is front-loaded and efficient, though the Args section duplicates the schema, adding some redundancy. Every sentence earns its place, but it could be slightly tighter.

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 mutation tool with 8 parameters and an output schema, the description provides sufficient context: purpose, partial-update semantics, parameter meanings, and return format. It lacks explicit prerequisites or error handling, but overall it is complete enough for an agent to use correctly.

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?

The input schema already covers all 8 parameters with descriptions, so the baseline is 3. The description's Args section largely repeats the schema, adding only minor nuance (e.g., 'feel: Subjective feel rating (1=terrible, 5=great)' vs schema's 'How you felt (1-5 scale)'). The added value is marginal.

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 clearly states the tool's function with a specific verb and resource: 'Update an existing activity's metadata' and 'Modifies one or more fields of an existing activity.' This distinguishes it well from siblings like delete_activity or get_activity_details.

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?

The description provides clear context for usage ('Only provide the fields you want to change - other fields will remain unchanged'), implying a partial-update pattern. However, it does not explicitly name alternatives or state when not to use this tool, so it stops short of a 5.

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