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

Annotations already mark readOnlyHint=false and destructiveHint=false, so the description correctly implies a write operation. It adds valuable behavioral context with 'Only the fields you pass are changed,' clarifying that unspecified fields retain their current values—a key nuance not present in annotations. It does not mention ownership requirements or failure behavior, but that is not expected given the annotations.

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 two short sentences, front-loaded with the core purpose, and lists the updatable fields without redundancy. Every phrase earns its place; the partial-update caveat is concise and useful.

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 tool with six well-documented parameters, one required, no output schema, and clear annotations, the description covers the essential operational context: what updates are possible and the partial-update behavior. It does not discuss return values or error scenarios, but such details are either unnecessary (no output schema) or implied. Minor gap: no mention of permissions or whether the tracker must be owned, but 'your' implies ownership.

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 coverage is 100%, so each parameter is well-documented. The description adds a global semantic note ('Only the fields you pass are changed') that goes beyond individual parameter descriptions and is critical for correctly using the partial-update pattern. It also maps high-level user goals (rename, description, visibility, alert frequency) to relevant parameters, aiding comprehension.

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 uses the specific verb 'Update' with resource 'Stock Tracker' and lists concrete actions: rename, change description, make public/private, change alert frequency. This clearly distinguishes it from siblings like create_watchlist or delete_watchlist by focusing on modifying an existing tracker's metadata.

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 gives clear context: use when you want to modify specific settings of an existing Stock Tracker you own. It implies partial updates via 'Only the fields you pass are changed,' but does not explicitly reference alternatives like add_to_watchlist or remove_from_watchlist, nor does it state exclusions. Still, the intended use is evident.

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