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

Annotations already cover read-only/destructive hints. The description adds the useful behavioral fact that it 'Answers without an API key,' and implies ongoing observation over time. However, it does not disclose what happens during watching, whether it blocks, or what the output looks like.

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 sentences, front-loads the core purpose, and includes a concrete example call. Every sentence adds value, and there is no redundant content.

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?

With a nested input object, no output schema, and no enumeration of actions, the description is incomplete for an agent trying to invoke the tool correctly. The single example helps but does not cover the range of possible operations or expected results.

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 only describes the top-level 'input' object, so the example call with {"action":"list"} adds some practical meaning. But the description does not explain possible actions or their semantics, leaving the nested parameter behavior largely undocumented.

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 states a clear verb and resource: 'Watch an indicator for change/activity over time.' This conveys the tool's monitoring purpose and distinguishes it from static lookup tools, though it does not explicitly differentiate it from sibling tools like whisper_walk.

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 no guidance on when to use this tool versus alternatives. It mentions 'Answers without an API key,' which hints at a usage condition, but there are no explicit when-to-use or when-not-to-use instructions, especially given the large set of sibling tools.

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